Try cleaning up the installer.
Start/run services.msc, scroll down to "Windows Installer" and double click
it. Stop the service if it is running, set the startup type line to
disabled. Click apply/ok and reboot.
Delete the contents of the temp folders, there may be a file in there
interfering with the setup routine of the installer. Get both:
C:\Windows\temp
C:\Documents and Settings\<username>\local settings\temp
Now reverse the first set of steps and reenable the Windows Installer (You
can just set the startup type to manual). Reboot.
Turn off all other running programs, especially your antivirus software. Use
ctrl+shift+escape, if necessary, to "end task" on everything.
Now retry installing some software.
sretno
