WmiApRpl (WmiApRpl) failed

Unloading the performance counter strings for service WmiApRpl (WmiApRpl) failed. The Error code is the first DWORD in Data section.
(Event error message)
Source
All performance counter names and explain text are maintained in string tables managed by the performance
counter subsystem (Perflib).
The current contents of the performance counter string tables are corrupted and cannot be displayed. To correct the problem, rebuild the string tables.
User Action

To rebuild the string tables, on the computer that displayed the message, at the command prompt, type

lodctr /r

The contents of the string tables are automatically rebuilt.
Source

Posted 21 August 2008 - 02:18 PM

The transfer mode should be set to ultra DMA mode [number]
Those errors indicate a damaged registry. http://www.testingreflections.com/node/view/4845 try the fix on this page.
Source 

This behavior occurs if the performance counters on the computer are corrupted. Follow the steps below to rebuild it.

1. Click Start->All Programs->Accessories, right-click on "Command Prompt" and click "Run as administrator".

2. At the command prompt, type the following commands. Please press Enter after each line.

cd %windir%\system32

Lodctr /r

3. Wait until you receive the following message, and then type 
exit

Info: Successfully rebuilt performance counter setting from system backup store

Then, check if the issue is resolved.

If it persists, the root cause may be one of the background programs. I suggest that you boot in Clean Boot Mode.

Clean boot

=================

Let’s disable all startup items and third party services when booting. This method will help us determine if this issue is caused by a loading program or service. Please perform the following steps:

1. Click the Start Button type "msconfig" (without quotation marks) in the Start Search box, and then press Enter.

Note: If prompted, please click Continue on the User Account Control (UAC) window.

2. Click the "Services" tab, check the "Hide All Microsoft Services" box and click "Disable All" (if it is not gray).

3. Click the "Startup" tab, click "Disable All" and click "OK".

Then, restart the computer. When the "System Configuration Utility" window appears, please check the "Don't show this message or launch the System Configuration Utility when Windows starts" box and click OK.

Please test this issue in the Clean Boot environment, if the issue disappears in the Clean Boot environment, we can use a 50/50 approach to quickly narrow down which entry is causing the issue.

Optimize Windows ( Vista - 7 ) for better performance

Source

No matter how fast or shiny computers might be when they are new, they all seem to get slower over time. That state-of-the-art PC you bought last year might not feel like such a screamer after you install a dozen programs, load it with antispyware and antivirus tools, and download untold amounts of junk from the Internet. The slowdown might happen so gradually you hardly notice it, until one day you’re trying to open a program or file and wonder, "What happened to my poor PC?"

Whatever the cause, there are a lot of ways to help speed up Windows and make your PC work better—even without upgrading your hardware. Here are some tips to help you optimize Windows Vista for faster performance.

Delete programs you never use

Many PC manufacturers pack their new computers with programs you didn’t order and might not want. These often include trial editions and limited edition versions of programs that software companies hope you will try, find useful, and then pay to upgrade to full versions or newer versions. If you decide you don’t want them, keeping the software on your computer might slow it down by using precious memory, disk space, and processing power.

It’s a good idea to uninstall all the programs you don’t plan to use. This should include both manufacturer-installed software and software you installed yourself but don’t want anymore—especially utility programs designed to help manage and tune your computer’s hardware and software. Utility programs such as virus scanners, disk cleaners, and backup tools often run automatically at startup, quietly chugging along in the background where you can’t see them. Many people have no idea they are even running.

Even if your PC is older, it might contain manufacturer-installed programs that you never noticed or have since forgotten about. It’s never too late to remove these and get rid of the clutter and wasted system resources. Maybe you thought you might use the software someday, but never did. Uninstall it and see if your PC runs faster.

For instructions, see Uninstall or change a program.

Limit how many programs load at startup

Many programs are designed to load automatically when Windows starts. Software manufacturers often set their programs to open in the background, where you can’t see them running, so they’ll open right away when you click their icons. That's helpful for programs you use a lot, but for programs you rarely or never use, this wastes precious memory and slows down the time it takes Windows to finish loading.

Decide for yourself if you want a program to load at startup.

But how can you tell what programs load automatically at startup? Sometimes this is obvious, because the program will add an icon to the notification area on the taskbar, where you can see it running. Look there and see if there are any programs running that you don’t want to load automatically. Position your mouse over each icon to see the program name. Be sure to click the Show hidden icons button so you don’t miss any icons.

The Show hidden icons button in the notification area

Even after you check the notification area, you might still have missed some programs that load automatically at startup. You can find and disable them using Windows Defender.

The Software Explorer screen in Windows Defender shows which programs automatically start when you launch Windows

If you’re unsure about whether a program should open automatically at startup, you can try disabling it, restarting your computer, and then using the program. If that causes any problems with the program, you can go back and re-enable it to start automatically.

For instructions how to use Windows Defender to check for programs that open automatically, see Stop a program from running automatically when Windows starts.

Note

Some people prefer to manage which programs load at startup using the System Configuration tool. For more information, see Start System Configuration.

Defragment your hard drive

Fragmentation makes your hard disk do extra work that can slow down your computer. Disk Defragmenter rearranges fragmented data so your hard disk can work more efficiently. Disk Defragmenter runs on a schedule, but you can also defragment your hard disk manually.

For more information, see Improve performance by defragmenting your hard disk.

Clean up your hard disk

If you want to reduce the number of unnecessary files on your hard disk to free up disk space and help your computer run faster, use Disk Cleanup. It removes temporary files, empties the Recycle Bin, and removes a variety of system files and other items that you no longer need. For step-by-step instructions on how to do this, see Delete files using Disk Cleanup.

Run fewer programs at the same time

Sometimes changing your computing behavior can have a big impact on your PC's performance. If you’re the type of computer user who likes to keep eight programs and a dozen browser windows open at once—all while instant messaging your friends—don’t be surprised if your PC bogs down. Keeping a lot of e‑mail messages open can also use up memory.

If you find your PC slowing down, ask yourself if you really need to keep all your programs and windows open at once. Find a better way to remind yourself to reply to e‑mail messages than to keep all of them open.

Turn off visual effects

If Windows is running slowly, you can speed it up by disabling some of its visual effects. It comes down to appearance versus performance. Would you rather have Windows run faster or look prettier? If your PC is fast enough, you don’t have to make this tradeoff, but if your computer is just barely powerful enough for Windows Vista, it can be useful to scale back on the visual bells and whistles.

You can choose which visual effects to turn off, one by one, or you can let Windows choose a bunch for you. There are 20 visual effects you can control, such as the transparent glass look, the way menus open or close, and whether shadows are displayed.

The Performance Options dialog box lets you turn on or off up to 20 visual effects

To adjust all visual effects for best performance:

1. Open Performance Information and Tools by clicking the Start button , clicking Control Panel, clicking System and Maintenance, and then clicking Performance Information and Tools.
2. Click Adjust visual effects.  If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
3. Click the Visual Effects tab, click Adjust for best performance, and then click OK. (For a less drastic option, select Let Windows choose what’s best for my computer.)

Try restarting if there's a problem

This tip is simple. If your computer seems to be running slowly and closing all the currently running programs doesn't help, trying restarting your computer. Restarting can fix performance problems where the exact cause is hard to pinpoint.

Add more memory

This isn’t a guide to buying hardware that will speed up your computer. But no discussion of how make Windows run faster would be complete without mentioning that you should consider adding more memory to your PC.

If a computer running Windows Vista feels too slow, it’s usually because the PC doesn’t have enough memory. The most sure–fire way to speed it up is to add more.

Windows Vista can run on a PC with 512 megabytes (MB) of random access memory (RAM), but it runs better with 1 gigabyte (GB). For optimal performance, boost that to 2 GB or more.

If you're going to the trouble of opening up your PC case to add more memory, you might as well boost the total to at least 2 GB. Especially if you're the sort of person who keeps a dozen e‑mail messages, ten browser windows, and six other programs open at once—all while instant messaging.

Another option is to boost the amount of memory by using Windows ReadyBoost. This feature allows you to use the storage space on some removable media devices, such as USB flash drives, to speed up your computer. It’s easier to plug a flash drive into a USB port than to open your PC case and plug memory modules into its motherboard. For more information, see Using memory in your storage device to speed up your computer.

Check for viruses and spyware

If your PC is running slowly, one dreaded possibility is that it might be infected with a virus or spyware. This is not as common as the other problems, but it is something to consider. Before you worry too much, check your PC using antispyware and antivirus programs.

A common symptom of a virus is a much slower-than-normal computer performance. Other signs include unexpected messages that pop up on your PC, programs that start automatically, or the sound of your hard disk constantly working.

Spyware is a type of program that is installed, usually without your knowledge, to watch your activity on the Internet. You can check for spyware with Windows Defender or other anti-spyware programs. For more information, see How to tell if your computer is infected with spyware.

The best way to deal with viruses is to prevent them in the first place. Always run antivirus software and keep it up to date. Even if you take such precautions, however, it’s possible for your PC to become infected. For more information, see How can I tell if my computer has a virus? 

Check your computer’s speed

If you try these tips and your computer is still too slow, you might need a new PC or some hardware upgrades, such as a new hard disk, faster video card, or more memory. There’s no need to guess the speed of your computer, however. Windows provides a way to check and rate your PC’s speed with a tool called the Windows Experience Index.

The Windows Experience Index rates your computer on five key components and gives you a number for each, as well as an overall base score. This base score is only as good as your worst-performing component sub-score.

Base scores currently range from 1 to 5.9. (There is no score yet of 6.0 or higher, although Microsoft plans to raise the ratings in the future as hardware improves.) If your PC is rated lower than 2 or 3, it might be time to consider a new PC, depending on what tasks you want to do with your computer.

For more information, see What is the Windows Experience Index?

Check for updates from the manufacturer

Have you visited the support website of your computer manufacturer to see if the company has released any updates for your specific model? Computer makers often issue software updates for programs they shipped with a PC, especially if the PC is relatively new.

You might be surprised how much information you can find by checking with the manufacturer. If other users are reporting the same problem you are having, the manufacturer might have already issued a fix, or at least provided information about the problem.

Ways to improve your computer's performance.

Boosting performance on Linux

A three-pronged attack on performance
(Related enhancements that can provide better overall speed for your Linux PC)
By Federico Kereki

A computer running Linux can outperform the same computer running Windows XP or Vista. Even so, you may be able to make your Linux system even faster. Here are three optimizations, at different levels, that can make your Linux system perform better.

As with all optimizations, you won't be able to tell whether you are really getting better results without doing some simple benchmarking. Many processes run on a normal Linux PC, and they can affect performance measurements. To minimize their impact, we will work at init 1 level -- single-user mode, in which only minimal processes run. Start a console (ALT-F1 will get you there), log in as root, and execute the init 1 command. This will shut down most services and applications, and let you get consistent results.

Even being in runlevel 1, you should then use the ps xaf command to check whether there's something running that shouldn't be; in my case, I discovered that the ddclient program was running (actually sleeping) and might have changed my results, so I ran kill ddclient to get rid of it.

Optimizing hard drive speed

Our first optimization targets the hard drive. In order to learn what hard drives you have, you can use cat /etc/fstab and mount commands. In my case, the first command produces:

/dev/hda3  /                    reiserfs   acl,user_xattr,noatime     1 1
/dev/hda1  /boot                ext2       acl,user_xattr             1 2
/dev/hda2  swap                 swap       defaults                   0 0
proc       /proc                proc       defaults                   0 0
sysfs      /sys                 sysfs      noauto                     0 0
debugfs    /sys/kernel/debug    debugfs    noauto                     0 0
usbfs      /proc/bus/usb        usbfs      noauto                     0 0
devpts     /dev/pts             devpts     mode=0620,gid=5            0 0
/dev/fd0   /media/floppy        auto       noauto,user,sync           0 0
/dev/hdd1  /media/disk2         reiserfs   defaults,noatime           1 2

while the second one says:

/dev/hda3 on / type reiserfs (rw,noatime,acl,user_xattr)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
debugfs on /sys/kernel/debug type debugfs (rw)
udev on /dev type tmpfs (rw)
devpts on /dev/pts type devpts (rw,mode=0620,gid=5)
/dev/hda1 on /boot type ext2 (rw,acl,user_xattr)
/dev/hdd1 on /media/disk2 type reiserfs (rw,noatime)
securityfs on /sys/kernel/security type securityfs (rw)

This shows my main disk is /dev/hda, with three partitions -- /dev/hda1, /dev/hda2, and /dev/hda3 -- and I also have a secondary disk /dev/hdd with a single /dev/hdd1 partition. Let's optimize the first drive.

The hdparm command ("hdparm" stands for "hard disk parameters") allows you to examine and modify drive configuration. Not all modifications are good: some will lower the performance, and some can even be wildly destructive, leading to data loss. The man hdparm command shows you all the options, and highlights the dangerous ones.

Let's start by viewing the current performance. The command hdparm -t /dev/hda does a test of the transfer speed, and produces a result like:

/dev/hda:
Timing buffered disk reads:   10 MB in  3.14 seconds =   3.18 MB/sec

That indicates a slow disk. I usually run this command a dozen times, discard the lowest and highest values, and average the rest. To do this, you can use a shell loop:

for ((i=0;i<12;i++))>

will repeat the test 12 times. You could also use script commands to do the discarding and averaging, but a simple calculator is enough.

Now, let's see the current disk parameters by using hdparm -v /dev/hda:

/dev/hda:
multcount    =  0 (off)
IO_support   =  0 (default 16-bit)
unmaskirq    =  0 (off)
using_dma    =  0 (off)
keepsettings =  0 (off)
readonly     =  0 (off)
readahead    =  0 (off)
geometry     = 16383/255/63, sectors = 156301488, start = 0

Normally, the first optimization to try is using DMA (Direct Memory Access, which means that the drive can directly store data in memory, for a speedier transfer), which can produce impressive results by itself. In my case, after setting the drive to use DMA by executing hdparm -d1 /dev/hda (the -d0 option would have turned DMA off; bad for performance!) I measured the speed again and got an increase to 16.25 MB/sec: more than five times the original speed!

We can try more options. We can change the IO_support value with the -c3 option, as in hdparm -c3 /dev/hda. On my system this produced just a tiny enhancement, reaching a speed of about 16.4 MB/sec, but it's worth keeping.

The multcount parameter shows how many sectors can be read in a single operation. The command hdparm -i /dev/hda produces somewhat confusing output which includes maxMultSect=16, which indicates we should run hdparm -m16 /dev/hda to allow the drive to read at its maximum rate.

Another parameter that has to do with reading more sectors is readahead. To get the best results, you have to experiment with different values; in my case, using hdparm -a1024 /dev/hda worked best. The combination of these two enhancements led to a speed around 33 MB/sec. To get there, I tried different combinations, starting with -a128 and going up through -a256, -a512, -a1024, and -a2048, but the speed peaked at -a1024; your results may vary. Of course, I ran my dozen tests after each parameter change.

I also tried different multcount values, from -m1 to -m16, and opted for the latter; trying -m32 gave me an error, warning me that the drive couldn't handle that value.

With all those changes, I managed to speed up the disk almost 11 times -- not too shabby! There are a couple more options you can try, but they could be risky. For instance, you could meddle with interrupts with hdparm -u1 /dev/hda or change the transfer options with the hdparm -X command. After testing them out, I did not get any further speed-ups, so I opted for leaving things as they were.

You can keep your values by running hdparm -k1 /dev/hda, but do not do this until you are really sure that they are correct and optimal. As an alternative, you can include your hdparm commands in /etc/init.d/boot.local, a file that includes commands that are run at startup time, at least on my openSUSE system; the startup command file may vary on other distributions.

When you reach this point, your drive is working at its best speed. Now let's work at a somewhat higher level, and optimize file access.

Optimizing filesystem access

Linux records the times when files were created, last modified, and last accessed. The latter usually implies a penalty on file access, since even if you only read a file, the system will update the directory entry for the file to record the latest timestamp. Since writes can be somewhat slow, doing away with this update should result in performance gains.

To achieve this speedup, you must change the way the filesystem is mounted. Still as root, you can cat /etc/fstab to get:

/dev/hda3    /                    reiserfs   acl,user_xattr      1 1
/dev/hda1    /boot                ext2       acl,user_xattr      1 2
/dev/hda2    swap                 swap       defaults            0 0
proc         /proc                proc       defaults            0 0
sysfs        /sys                 sysfs      noauto              0 0
debugfs      /sys/kernel/debug    debugfs    noauto              0 0
usbfs        /proc/bus/usb        usbfs      noauto              0 0
devpts       /dev/pts             devpts     mode=0620,gid=5     0 0
/dev/fd0     /media/floppy        auto       noauto,user,sync    0 0
/dev/hdd1    /media/disk2         reiserfs   defaults            1 2

Disk drive partitions / and /dev/hdd1 are the best candidates for the optimization, since /boot is used only at boot time, /swap is out of bounds (Linux uses it for its own needs), and the others are not hard disks.

The change is easy: using any text editor add ",noatime" to the options in the fourth column, and remount everything with the mount -a command.

How to test the performance gain? I first tried using the bonnie++ package, but the results weren't conclusive, since its tests are not specifically oriented to file access.

Instead, I opted for a more "do-it-yourself" test. I created a thousand files and copied their contents to /dev/null, timing the copy. I did the former by

for ((i=0;i<1000;i++))>$i ; done

and the timing by

time cp * >/dev/null

both with and without the noatime option. The results showed a small performance enhancement, which is logical, because now the file access time isn't updated after every access.

Now that the drive is working as fast as possible, and that we optimized access to files, it's time for the last optimization: getting commands to load faster.

The rest of the article here

Federico Kereki is an Uruguayan systems engineer with more than 20 years' experience developing systems, doing consulting work, and teaching at universities.