Well, I tried the old msconfig, (after renaming the FileCache.dat file) selected diagnostic startup (basic tasks and services) rebooted, ran RegSupremePro and sure enough, after about 3 minutes the file cache was updated and the program was ready to go. Then checked the FileCache.dat file in the data dir, copied it to a safe place and renamed it just in case. Rebooted, (using normal startup) ran RSP and voila, it worked. No more nagging screen and the .dat file is still intact. (quite a bit larger than the one I copied from the other computer, but then it only has two HDs 80GB and 6GB and 4 partitions) So feeling a little brave, I decided to give the JV16 PT a try because it still has this problem of shutting down after selecting "YES" to let it update the cache. No joy with this one, it still shuts down. Works fine after copying the .dat file from RSP to the cache dir. Going back to RSP, I'm not sure what program caused it to hang up like that, but I have a sneaky suspicion it was either Ad-watch from Lavasoft or my antivirus program (PCCillin from Trend Micro). I hope any of this helps the gurus at jv16?