Black Screen... no game

I was happily playing away yesterday evening, no problems at all. But when I went to log in again later on, the computer connects to Arena.net as usual, downloads a few files and then the screen goes black and bringing up Task Manager tells me that it's "Not Responding".

The only thing that changed between me logging off and trying to get back on was that Norton Security did a live update. I've checked the configuration options in the firewall and Guild Wars is set to "Allow"

I've tried...

reinstalling
deleting the .dat file and reinstalling
uninstalling from 'Add remove programmes'
uninstalling from the 'Uninstall Guild Wars' option on the start menu
Downloaded the client and all 4,000 odd files from fresh
Installing from the cd

I can get on from my partners machine. Just not mine.

System:

P4 3.2 ghz
1gig Ram
Geforce 7600 gs
Dual monitors

The only thing that changed was Norton, but disabling the firewall hasn't made a jot of difference... and I'm getting to the stage where I'll probably end up reformatting soon... and I don't really want to, it's only been three weeks since the last time.

All drivers are up to date and nothing on those has changed anyway. So it can't be that.

Any help appreciated, thanks..

Try completely disabling Norton or if it has one setting it to game mode, or perhaps it has caused problems with Dx?

The only thing I know is that I hate Norton, so I can't give you much more advice.

Oh and I have the same gfx card as you and I've had no problems with it todate, just incase you think it might be that.

Thanks, Warrior.. I've admitted defeat and started a reformat. I think Norton may have done something to the registry... and I was going to farm for some NF greens this weekend. Ah well...

I'm pretty sure it's not the card either. It's been running NF on max settings with 4xAA and no probs at all bar the usual town lag when busy.

Edit: This is solved now. The reformat seems to have done the trick. I'm still blaming Norton.

EDIT- Reformat ftw.

Back to lovely normality.

Just got to reinstall all my apps now... >.<