It can't be Vista ...
How about telling us WHEN .. and under WHAT conditions you get all these blue screens?
Probably a RAM stick problem .. or something like that.
Has RAM been added?
Bernie.
Packard-Bell: not a good choice.
Vista: not a good choice.
Packard-Bell + Vista = Nightmare.
As one of the guys earlier said, you need to note when the blue-screens happen - what app you are using, what other apps are running, how long the PC has been on etc.
I agree it is not Vista but your computer hardware. You should have 4 GB of ram installed to prevent the computer running out of memory . If you dont like Vista then migrate to Windows 7 and your problems will mostly disappear. Windows 7 will run perfectly on your computer as it hasn't the demands of Vista. With support for XP slowly going time to make the change to Windows 7