By "nothing happens", I mean that the small RegCleaner window opens, but none of the buttons will respond to a mouse click. It appears that the program has frozen, and I have to close PT by right clicking on the program in the taskbar and clicking close. Once I re-start PT, everything works fine after that. This problem does not occur 100% of the time I open PT, just the vast majority of the time. Before I wrote this post, I tried to recreate the problem, and just like when you call a repairman, everything seems to be working fine this morning. Would still appreciate any advice you can give, though, for the next time this problem occurs. Thank you.