The goal of my suggestion above was to remove all SU free and Pro and then downlaod, install SU free. You post indicated you did not get rid of SU Pro. Make sure you use the add / remove programs function and delete any thing associated with SU, run registry cleaner maybe even several times, download and install free. If that odes not work use the windows explorer ( ref start, serach) and do a wild card search of any su files ie * Su pro*, key; etc and maybe you can find the problem file. You will have to run combinations although the suggestion above about the file would be a good start