Sorry, I don't think I was clear enough on my last reply. I wondering if the user you login with is the 'administrator' user, not an admin level user. The paths for where things are installed can differ if you install with the built in administrator user. For example if your user is user1 then the path for the license file would be:
C:\Documents and Settings\user1\Application Data\WebAssist\Expression Web\CSSSculptor
However, if you installed as the Administrator user the file may not be in this location, but may instead be in one of these two:
C:\Documents and Settings\Administrator\Application Data\WebAssist\Expression Web\CSSSculptor
C:\Documents and Settings\All Users\Application Data\WebAssist\Expression Web\CSSSculptor
To get past this issue you will need to have a license.dat file in the correct location. If the location is different from the place that the activation is looking for it you will be prompted to activate again. Please take a look in all three of these locations if they exist for you and find the license.dat file. If you find the file copy it to the other locations. This should allow it to work for you. If you have problems with it after this please let me know and I will open a ticket for you and get this to our engineering team.