I've downloaded the Demo version of Vegas 4.0. While clicking on the file it is giving an error : "Unable to 
write to the temp directory in c:\documents and Settings\Local Settings\TempCheck that you have write access o the directory."
I've seen all the file permissions and unable to analyse where the paroblem persists.
And if I login as a different user, the installation starts and suddenly after installing a few 10 files gives 
an error "Unknown erroe, installation will now abort" 
Please try to solve this problem if anyone can..