Thought I would share what worked for me....
I updated my ZA with no problems but when I re-started my XP OS it was VERRRY slow to boot the tool bar and desktop icons about 3 min or so, it seemed to be hanging in the same way a corrupt registry hangs when it's searching for the reg file, i.e. I can see the hardrive light making slow blinks as it searches the disk for needed files. I shut down the PC and noticed it was hanging on the shut down as well.
As ZA was the only recent system change it was easy to assume that the upgrade was the cause of the problem. I went to un-install and a pop-up stated that there was already a process going so I could not continue with the uninstall (not verbatim)
I shut down my ZA and tried to uninstall, this time no pop-up, I re-started my pc and this time did a fresh install rather than an upgrade.Re started PC at prompt, re booted and found that after the new reg files were done writing that the desktop booted as it should.... no more slow boot or shut down.
I have since upgraded again by un-installing/rebooting/re-install new version and have had no issue since.It seems that IN MY INSTANCE the install software had left something running and at boot and shutdown it was still trying to execute the upgrade install and that this was causing slow boot and shut down.
I hope this may sole your issues as well.Mark-
Operating System:Windows XP Pro
Product Name:ZoneAlarm Internet Security Suite