The system administrator

Source

"The system administrator has set policies to prevent this installation” error

The solution to this is to fix the local security policy.

1. Open control Panel and go to Administrative Tools.
2. In Administrative tools open Local Security Policy.
3. In Local Security Policy right click Software Restriction Policies and click “New Software Rectriction Policy”.
4. Now Left click on software restriction policies and in the right-hand window you should see enforcement.
5. Double-click on enforcement and set the policy to apply to “ALL USERS EXCEPT LOCAL ADMINISTRATORS”

Now approve the changes and see if you are now able to install software.

Alternately several people recommended the following but I’ve found the above steps fix the problem in 98% of cases.  

If you are unfamiliar with the registry…. stop reading.

1. Browse the registry to HKLM\Software\Policies\Microsoft\Windows\Installer
   Create: DisableMSI       Type: REG_DWORD  value = 0   (0 should allow you to install it was originally 1)
2. Browse to HKEY_CLASSES_ROOT\Installer\Products\
   Search the list for the product that is causing the error.. delete the folder in the products folder…  this may also correct your error…

***** UPDATE ******
I’ve gotten alot of comments that they cannot find secpol.msc.  This is because it is not included on Home versions of vista. However, I now believe I have an answer even to this.  I have spent the last hour reviewing the registry changes that are made and have narrowed down the value that is changed when you set the above policy.  The Value changed is a dword value :

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\{A541BD3D-1A70-4D7B-BC99-CF1ADFC0DE9F}Machine\Software\Policies\Microsoft\Windows\Safer\CodeIdentifiers\PolicyScope

It is changed from 0 to 1 when you set it not to apply to administrators.  When you set “new software restriction policy the following tree is populated:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Group Policy Objects\{A541BD3D-1A70-4D7B-BC99-CF1ADFC0DE9F}Machine\Software\Policies\Microsoft\Windows\Safer

I am not sure if you need the whole tree to get it to function or just the value I have included 2 Registry files to run.   The first includes just the policyscope value of 1 the second includes the entire “Safer” tree that was created on my machine when I added the software restriction settings.

Click here to download just the PolicyScope setting.  (download and run first to see if it fixes your problem.)

Click here to download the entire “Safer” tree that manually adds the fixed software restriction settings. (try this if the above reg file does not fix your problem.)

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This is what finally worked.

I turned my User Account Control off here:
Start-Control Panel-User Accounts-Turn User Account Control

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Another solution...vistasecurity

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Windows 7 solution: (try to be logged with administrator rights or as administrator)
Right click the program and select “run as administrator”.
**If that option is not available** . . .go to
Start-All programs-Accessories
and right click on the command prompt, then select “run as administrator”.

From within the command prompt, navigate to the folder containing the program you want to run, then type the file name to run it.