Getting that magic 100 can, at times, be a challenge. Do not despair, though! Have you run Registry Cleaner using the most aggressive cleaning policy? That should help. Additionally, there are registry keys and entries that Registry Cleaner cannot delete because the programs that install them set their permissions to prevent deletion. PowerTools will usually indicate those entries when you try to delete them after a scan. On my system, Adobe Acrobat is the biggest such offender. If I really want to get rid of such entries, I manually reset their permissions to allow me to delete them myself - I use Registry Workshop, but you can also use Regedit. Do this carefully - you can disable programs or your system if you're not careful. If you decide to go this route, research registry entry permissions (or something similar) on Google and get a little smarter on the process. I have found that these types of 'latent' registry contents will prevent PowerTools from indicating a Registry Health score of 100.