Windows.old

Source
How to restore your personal files after you perform a custom installation  of Windows Vista or of Windows 7
In some scenarios, you may be unable to perform an upgrade from an earlier version of Windows. If you cannot upgrade, you may have to perform a custom installation. When you perform a custom installation of Windows Vista or of Windows 7, Windows creates a Windows.old folder that contains the files from your previous system. You may want to recover your personal files from the Windows.old folder, and move them to the custom installation of Windows.
To have us restore personal files for you, go to the "Fix it for me" section. If you prefer to restore personal files yourself, go to the "Let me fix it myself" section.

Fix it for me
To fix this problem automatically, click the Fix it button or link. In the File Download dialog box, click Run, and follow the steps in the Fix it Wizard.

Restore personal files
Microsoft Fix it 50582

Notes

• The Windows.old folder that contains the files from your previous system should exist on the computer.
• You may receive some error messages in the command prompt when you run the package. You can ignore the error messages.
• This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
• If you are not on the computer that has the problem, save the Fix it solution to a flash drive or a CD, and then run it on the computer that has the problem.

Your Firefox profile will be in:
http://support.mozilla.com/en-US/kb/Profiles
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http://support.microsoft.com/kb/811151/en-us
How to restore a Windows 7-based computer to a previous Windows installation by using the Windows.old folder
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Windows 7 - Windows.old folder - Restore into a new installation
by lordbob
Information

This will restore the files and folders from the windows.old folder.
This means that any documents, settings, and programs will be restored to their previous positions and settings.
It will look similar to your previous installation, but not exactly the same! There will be some differences!
YES, this works in Vista, as well as Windows Seven. The instructions are EXACTLY the same!

Setup:

1) Make sure that you want to do a new installation. If you are, then boot into the Install Disk and complete the installation.

2) Now you want to restore some of your old files? OK, read on!
Let's begin:
1) Insert your Installation disk into your DVD drive, and reboot. Make sure you can boot from the DVD.

2) Press any key to boot from CD when the option appears.

3) At this point, you have already done a clean install over your existing installation.

4) Select "Repair Your Computer" from the installation menu (see screen shot below).

Click this bar to view the full image.

5) Select your Windows installation you want to restore to.

6) Select Command Prompt. This will bring up the command prompt window.

   Warning

This starts getting complicated, and if you do something incorrectly, it could cause problems. Make sure you have your windows.old folder backed up, as well as your current installation (if needed).

Type each command EXACTLY as it is written! If you misspell what is in the code box, you will misspell the folder, possibly causing problems or errors!

   Note

When you type one or more of the commands at the command prompt in the following steps in this section, and you then press ENTER, you may receive the following message:
The system cannot find the file specified.
If you receive this message, go to the next step in this section, and then type the command in that next step.

7) Type the following commands in, one at a time. Press ENTER at the end of each line. This will rename the windows.old folders, in preparation of being moved.

Code:

c:

Code:

ren Windows Windows.backup

Code:

ren "Program Files" "Program Files.old"

Code:

ren "Users" "Users.old"

Code:

rmdir "C:\Documents and Settings"

8) Now we will move the folders over the new ones, restoring your old settings and files. Again, type the commands in one at a time, pressing ENTER at the end of each. If you are using a drive other than c: for your windows installation, replace c: with that drive letter!

Code:

move /y c:\windows.old\windows c:\

Code:

move /y "c:\windows.old\program files" c:\

8a) When the previous Windows installation was Microsoft Windows Server 2003, Microsoft Windows XP, or Microsoft Windows 2000:

Code:

move /y "c:\windows.old\documents and settings" c:\

8b) When the previous Windows installation was a different version of Windows Vista or Windows Seven:

Code:

move /y c:\windows.old\users c:\

9) Now we need to restore the boot sector of the previous installation.NOTE: D: represents the DVD drive in the following commands. If the DVD drive on the computer is represented by a different letter, such as E:, use that letter in the command.
When the previous Windows installation was Microsoft Windows Server 2003, Microsoft Windows XP, or Microsoft Windows 2000

Code:

D:\boot\bootsect /nt52 c:

When the previous Windows installation was a different version of Windows Vista

Code:

D:\boot\bootsect /nt60 c:

10) Restore the Boot.ini file for the previous Windows Installation of Windows XP or Windows 2000
Note: Only follow these steps when the previous installation is Windows XP or Windows 2000.

Code:

c:

Code:

attrib boot.ini.saved -s -h -r

Code:

ren"boot.ini.saved""boot.ini"

Code:

attrib boot.ini +s +h +r

11) Exit Command Prompt by typing:

Code:

exit

Then restart your computer.

Your Windows installation will start as normal, with the newly restored files and settings.

   Warning

This does NOT work perfectly!!!
When I used this, I still encountered some errors, such as TWO Program Files folders, and missing icon pictures.

This is NOT a recommended way to do a restore! It will work, but you should back up your data and take the time to either create a restore image, or reinstall your files.

It WILL work just fine for files such as those in your Documents folder.

For anyone that wishes to use it, I hope it works for you.
I hope this tutorial will help many a person, and provide a solution.
~Lordbob
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The dat files of registry are in
C:\Windows.old\Windows\System32\config
http://support.microsoft.com/kb/256986/en-us
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Getting-Operating-System-Version-Info-Even-for-Seven
For windows XP
Quickly Find Your Windows Version and Architecture Info
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