Hi again,
I solved the restart hanging problem thus:
1- Downloaded v.126
2- Uninstalled V.127
3- Restarted computer
4- Win XP was now able to restart (with short delay)
5- Removed Ccleaner from Program list in Zone Alarm
6- restarted computer
7- Closed all programs (including Zone Alarm and Avast Anti-virus) in systray
8- Installed Ccleaner v.126
9- Fingers crossed! All seems well.
P.S.: I ran several more tests after posting this message; ran Ccleaner and Issues tasks separately and in concert; re-added Ccleaner.exe to Zone Alarm's Programs List; restarted after each operation; all IS definitely WELL !
My guess is that the problem lies with v. 127.