computer locking up out of no where

all of a sudden when i am down loading a large file.my compter locks up,and the only way to get any response is to shut her down by holding in the power button. don't know where this is coming from,i am using nbz o matic pissing me off like a third to half way thru and it locks up.nbz not responding whole copmuter not responding.any help would be better than nop help

 

Do a virus & spyware scan, then update windows. Also check to make sure you have enough free space.

 

thanks for the reply ,i guess it was nbz loader conflicting with vista. i think no problems as of now