Programs are pretty consistent during installation processes in that most of them use the C:\Windows\TEMP folder (or C:\TEMP or C:\TMP ) to place their setup files temporarily while it completes the installation. However, since so many programs do this and lots of them don't empty those folders due to poor programming, you wind up with the TEMP folder full of files without realizing it.I would start by going to the C:\Windows\TEMP folder and emptying it completely (then empty the recycle bin) and if you don't have any folders under C: called TEMP and TMP, create those also just in case some program needs that location instead of the folder under C:\Windows.
Now reboot the computer, and try the installation again.
