I just made another Registry Cleaner run and again had errors though the handling was different this time:
1. There were 10 entries selected for deletion
2. All 10 were backed-up as requested
3. Errors were shown in the status window below for 2 of them: "Failed to modify "HKEY..."
4. This time these keys remain behind and weren't removed
5. I run Registry Cleaner again and again get the errors
6. I can find no evidence that these errors were encountered in the first place
Ignoring the oddity of my first report (it SAID it couldn't modify the keys but then actually did), in this second report it can't modify the keys and leaves them behind.
What I find problematic is that jv16 does not appear to log the errors anywhere, so if a user is not paying attention to the status window, or closes that window inadvertently, there is no way to identify that the cleaning did not occur successfully.
BTW and FYI it appears that one may be able to get-around the issue of PT's not being able to delete keys (the Permissions problem) by running PT under Sysinternal's PsExec as System, i.e. this:
psexec -s -i "C:\Program Files (x86)\jv16 PowerTools 2013\jv16PT.exe"
I've used psexec in the past to run Regedit for this purpose (to delete keys) but it only recently occurred to me to try it with jv16PT and I would be interested to hear any other comments about this.