Ongoing PC issues!

[TransAm]

Thanks to everyone who posted in my previous topic

Ok now I keep getting the blue screen of death

Since I started having 'problems' I have replaced the following:

Motherboard

Then, reinstalled windows. No problems for a few days, but the PC started restarting itself occasionally. I then replaced the:

RAM
VGA Adapter

Again, the problem persists, and I get messages that certain data on C: is corrupt. Chkdsk ALWAYS fixes the problems, but regardless:

This weekend I fitted a second HDD (Slave at the moment) and copied my contents of my C: to the new drive, so I have a backup, just in case. I also fitted a new PSU at the same time.

I am now getting the blue screen of death once or twice a day.

Two questions:

1. Is there any quick way to update ALL my drivers and delete any drivers that might be causing conflict (i.e. the old VGA adapter drivers spring to mind)

2. Would corrupt data on the HD cause blue screen of death? BSOD tells me to check VGA drivers, memory and bios. Well I am sure the VGA is working ok as I play doom3 and Pirates! successfully, memory is new centon 2x512mb sticks, and bios I think is ok, I've disabled any caching options and put all settings onto autodetect where I can

Anyone got any ideas what I should try next? My wife is trying to run a forum and website from our home PC, so you can imagine the distress it is causing her!!

Now it might sound like I have a lot of spare PC components lying around that are actually serviceable, but I don't feel stupid about replacing things as I plan to build a second PC for my front room, a little 'media' PC...