PC Freezes on Launch

Hi Folks

When I try to launch Guildwars most of the time my PC freezes and I have to reboot.
This happens about 50% of the time.
When I try to re download the client this also happens.
I have no problems with other MMO's.
Any idea what might be the cause of this?

Any help appreciated

System Info :

Motherboard : Asus P5Q
Processor : Intel Core 2 Duo E8400
GPU : Ati Radeon HD4850
Memory : 3326MB RAM (DDR2 6400)
OS : Windows XP Professional Service Pack 3 (32bit)

Is it possible that the problem is caused because I installed it in program files? I just copied the whole thing out of there and now its working fine =) Thanks for the input ^^

It's possible that it's caused by a corrupt gw.dat file. You could rename (or delete) it and use the -image command to rebuild it.

if possible try copting the dat file from a friends computer and deleteing your and psting the copy onto yours faster then redownloading the whole thing again