Cant Install any programs in Windows XP, Vista or 7

your getting the error "administrator has set policies to prevent this installation"

This could be caused by a Virus. Either way, you can fix this by editing the registry. Some things to keep in mind. If it is a virus, you don't want to reboot because the virus could cause more damage. But, if you are going to edit the registry you need to reboot in order to apply the settings. This makes things interesting.

You will need to apply the registry fix first, then try to scan your computer for Viruses and hope it removes the virus before you reboot.

How to Fix the Error:

For Windows XP:

• Click Start
• Click Run
• Type regedt32 in the run box and click OK
• The Registry Editor will open, browse to the Registry Location below:
  
• HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Installer
• In the Installer Folder of the Registry. We need to create a new Key. Right Click in the Installer folder window and choose New, Dword, and name it DisableMSI. Then open the new Registry key and set the Value to 0 -which is a zero
• Now you Done fixing the error, but you still need to Scan for Viruses before Rebooting. The steps for how to scan with Antivirus if you cannot install Antivirus is below.
  

For Windows Vista and Windows 7:

• Click Start
• Type regedt32 in the search box and click OK
• The Registry Editor will open, browse to the Registry Location below:
• HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Installer
• In the Installer Folder of the Registry. We need to create a new Key. Right Click in the Installer folder window and choose New, Dword, and name it DisableMSI. Then open the new Registry key and set the Value to 0 -which is a zero
• Now you Done fixing the error, but you still need to Scan for Viruses before Rebooting. The steps for how to scan with Antivirus if you cannot install Antivirus is below.

How to Scan for Viruses without Installing Antivirus:

You be able to use another computer in order to do this. The computer can be running Windows XP, Vista or Windows 7. Then you must go to that other computer. Download and install and Antivirus or Antispyware or your choice. ASG has a list of Free Antivirus and Free Antispyware. ASG recommends you start out scanning with SuperAntispyware because it is the easiest to use in this situation. Either way, after you get your Antivirus or Antispyware installed. You want to turn it OFF. Then you need to go to the program folder and create a zipped copy of the Antivirus or Antispyware program that you installed. It sounds hard but its pretty easy. Once you get the Antivirus onto your computer, its easy to run a Scan. Keep in mind you want to Scan your computer with at Least 2-4 different Antivirus and Antispyware programs before you reboot. This way you have a good chance or completely removing the virus.

For Windows XP, Windows Vista & Windows 7:

Go to C:\Program Files\Name-of-Antivirus-or-Antispyware

Then right click on the Folder and choose Send to, Compressed (Zipped) Folder.

Now you should be able to find that Zipped folder you just created. You will need to copy that folder onto a Disc or Thumb/Flash Drive and take it to your infected computer. Then copy the Zipped folder onto your Infected computer and unzip it.

Right click on the Zipped File, choose Extract All. Then keep clicking OK on every window it gives you during the extraction. After it's done extracting you can Open that folder and run the Antivirus or Antispyware program that is inside the folder. If it does run properly for you then you will need to try another Antivirus or Antispyware program. ASG has tested SuperAntispyware, Antivir and SpywareTerminator in this way and all 3 work well.

OTHER ALTERNATIVES:

If you need more Help removing the Virus or Spyware from your computer, click on the link below that includes additional steps for removing Malware from your computer.

ASG - How to Remove Malware

You can use an Antivirus Boot CD. This is a process where you would download a New Copy of an Antivirus Boot CD, burn it to CD and Boot your computer from the Disc to scan for Viruses. ASG does not support this method as it can be very complicated walking a user through this process and each computer works differently when booting from a CD. ASG suggests consulting a computer repair service for further help with this type of Removal.