Vista wont complete shutdown

[Chrono]

a few weeks ago, i posted problems about vista making apps not respond often, and failing to shutdown... since then, i have tryed updating drivers, bios update, a few other things listed too, but today i tryed to start fresh again, and wipe windows.

i could have sworn this would have worked, but alas, it still fails to shutdown 90% of the time... it just stays on 'shutting down' step. this happens for both tryin to shutdown, or restart, makin updating anything annoying.

everything worked fine when i was running XP, but now it doesnt wanna work.

the only thing i changed in my comp was a new PSU about 1 week before i installed vista... could this have anything to do with it?

im not sure if vista is still making my apps not respond, that is something that only time will tell, but what is the cause of this? could it be vista itself being bad? or just my unfortunate setup

 

[KSoD]

Okay are you sure the new PSU can handle all the load? 2nd how long are you waiting before you force shut down your PC? I knwo that after a couple of the updates it took my system almost 5 minutes to shut down and restart.

 

[Chrono]

powersupply is a 750W thermaltake tough power, traded up from a generic 450, so im sure it can take it.

normally i wait 2 or so mins b4 i force shutdown, but when it was updating, i was waiting over 10 mins... should never take that long


[EDIT: also, i dont suppose its normal for it to crash often, as ive been running fresh for a few hours now, and when opening my computer sometimes, it stops responding, and im unable to just close that down... the cursor turns into one of the loading circles, and just stays that way... makin me have to force reset to do anything... any ideas?]