Just run the one you downloaded.
If it is the SSE-2 version and your system doesn't support it, it will tell you.
Thanks again Eddy, I really appreciate your help.
Okay, I downloaded the avastclear.exe file but could not run the uninstaller as it said I needed to have Administrator privileges. I have always been the only one to use this computer and was set up as the Administrator. I checked under User Accounts and I am STILL showing as the Administrator so why would this happen?
This is getting so frustrating - why does Avast have to make everything so difficult??? It would be really simple to just include an uninstaller with their software. Or else make it capable to for people to uninstall it using Add/Remove.