Vista : All programs screwed after antivirus installation

[ragegoh]

As mentioned in the title.

Specs are as follow :
CPU : Core 2 Duo 7300 (2.66GHZ)
OS : Vista home premium
RAM : 4GB DDR2 800 (2 x 2GB)
Video Card : GeForce 7300GE

The problem arise as long as i install an antivirus program. Any kind of antivirus program. AVG / Norton / AVAST / ESET.

I did not install all of them or two at once. I only use one antivirus one point of time.

Whenever the antivirus is installed, all my programs .exe don't work anymore.

Just this week, most of my games are not working anymore. It crashes as long as i launched it.
Example :
iw4sp.exe has stopped working

First case :
I installed norton, it scan all most of my .exe files as virus. When i launch task manager, there is an error saying that .exe is an unknown extension. I found the fix by adding in a registry file. But when i restart my desktop, the problem still exist. (Problem as in all .exe are unknown extension).

Second case :
I can't take it any longer because of the first case above. I reformatted my desktop. There is no problem. But again, the problem arise today when i installed AVG. I tried to launch the avg control centre as i intended to scan my computer. An error pop out saying destination path is not valid. I dont remember the exact error message. But this is part of the error message.
Not only AVG is facing problem, ALL the other programs pops out the same error as long as i launch it.



Is there anyone here who knows the fix for this problem?

Thank you.

Regards,
Andrew

[EINSTEIN_007]

Have a look at the below topic which might give you some ideas:

http://support.microsoft.com/kb/167452