Ok I did event viewer, here is a recent error when trying to install antivirus software:
The description for Event ID ( 11324 ) in Source ( MsiInstaller ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: Product: PC-cillin 2003 -- Error 1324.The path Documents and Settings contains an invalid character., (NULL), (NULL), (NULL), (NULL), (NULL).
I also got another similar error when trying to install a different brand antivirus software.
So yes there are problems with programs not installing, and not just antivirus software.
Its says this in the path to executable box: C:\Windows\System32\msiexec.exe