BleepingComputer.com: Installing - Uninstalling Applications - System Hangs

Vista Home 32bit - SP1 not installed
Sorry if this covered somewhere else... my searches didnt show anything - please point me at it

Recently I have started to experience difficulties installing or uninstalling applications (I have no valid pre-problem restore points to go back to)
The wizard runs fine until it is about to finish and then it hangs
- The wizard cant be cancelled
- I cannot start any new apps
- TaskManager and Procmon cant end the wizard (tend to have them started before attempting to un/install
Only way I have found to get out of this is to switch off and restart - hardly ideal

All scans show nothing is wrong
CCleaner runs OK and clears lots of /temp/ junk
I can update registry using regedit OK - spybot pops but allows the update
I can use MSconfig - spybot does its stuff and all is well

Any ideas, things to check .... wild shots in the dark appreciated

I'd start by looking for errors in your Event Viewer - and seeing if any of the programs have installer/uninstaller logs that you can have a look at.

Try turning off UAC temporarily to see if that fixes it (that'd mean it's likely to be a permissions error)
Have you given SpyBot admin permissions to run?

Usasma - thanks for the response
Running with UAC off ...I know I know I shouldnt but its such a a pain.
Spybot running OK, but somewhere I do think it is a permission issue

Update
=====
I seem to have regained some stability - though I dont know if I am fixed
Something I maybe should have mentioned -sorry- I had been running with selective startup (trying to get rid of un-needed progs/services)

What I did since I posted ..
Started to selectively disabled progs in startup (msconfig) Spybot, SuperAntivirus, AVG

On startup get the sys config box popping to say I had changed something , OK this and continue
Sometimes the system would be alright and I could launch apps (sometimes it would hang , but poweroff/start safe/ reboot got things fixed) - but it still got hung up on Un/Install of a prog

Then I unchecked ZoneAlarm (though i think on reflectiion anything would have been any prog ) and then thought it wasnt going to be that so checked it again. On exit APPLY wasnt grey'd as i had changed something ,,, but i clicked OK instead of cancel
Anyway on next restart I got the normal System Config Util box - clicked OK ...system hung ! Nothing will launch
This may be a coincidence or may be the straw that did for the camel but I now have a useless system that I cant even look at

Cycled through Switch off/Start Safe/Restart a couple of times but always with the same result - configuration has changed, OK, Hung !

Decided to go back to Normal Startup
This worked - though I did get all the redundant stuff starting. Spybot did its stuff requesting confirms for all the 'now new' stuff - CCleaner having "tidyd up"
Rebooted agian to get a "clean" start - could launch apps and un/install things
- I now use Spybot to not allow things to start and all seems well

Bottom line - dont know what I did to break it - probably got something out of step, and as I say it may not be fixed but for now it is stable
Plan to leave well alone until I have sometime and then -rip out all the junk and un-reinstall the bits I need/want ...and hopefully end up with a cleaner setup. Guess this would have been a better PlanA

If anything else comes to light I will append.

Thanks again for your time
Ciao

FWIW - I don't practice what I preach I turn UAC off on my personal system - but if I get infected I can restore and image and be back up and running in 20 minutes.

I don't recommend the use of MSCONFIG as a startup manager. It wasn't designed for this - and it frequently will complicate things when we're trying to troubleshoot an issue.
I recommend (in Vista) the use of Windows Defender for routine startup maintenance - and the free program Autoruns ( http://technet.microsoft.com/en-us/sysinte...s/bb963902.aspx ) for mare advanced operations.