Screen freeze, sound goes on (specs included)

I have been playing Guild Wars for over a year now. I never had problems. I recently bought a new computer and after about 2/5 minutes of playing. My screen freezes.
This happens in any location in the game. The weird thing is that the sound goes on normally.

I already tried changing Drivers but it didn't fix the problem

There are no errors showing up when my screen freezes.

These are my systems specs:

Windows: Windows XP5.1 (Build 2600) Service Pack 2
Internet Explorer: 6.0.2900.2180
Memory (RAM): 1024 MB
CPU: AMD Athlon(tm) 64 Processor 3000+
CPU Speed: 2007,9 MHz
Sound card: Realtek AC97 Audio
Display Adapters: RADEON 9600 SERIES | RADEON 9600 SERIES - Secondary | NetMeeting driver | RDPDD Chained DD
Screen Resolution: 1024 X 768 - 32 bit
:
Network Adapters: NVIDIA nForce Networking Controller - Pakketplanner-minipoort
CD / DVD Drives: D: LITE-ON DVDRW SHW-160P6S | E: LITE-ON DVD SHD-16P1S
:
COM Ports: COM1
LPT Ports: LPT1
Mouse: 5 Button Wheel Mouse Present
Hard Disks: C: 88,6GB | F: 97,7GB
Hard Disks - Free: C: 54,8GB | F: 95,5GB
USB Controllers: 3 host controllers.
Firewire (1394): Not Detected
:
Manufacturer: American Megatrends Inc.
Product Make: K8N
:
AC Power Status: OnLine
BIOS Info: ATAT COMPATIBLE 090605 A M I 9000506
Time Zone: West-Europa (standaardtijd)
Battery: No Battery
Motherboard: ASUSTeK Computer INC. 'K8N'
Modem: Not detected

Any help would be very appreciated. I miss playing GW alot.

I have the same problem where the screen freezes. I've had this problem for a while now and I don't know why it happens. The game runs fine on my brothers computer which is the same as mine accept the sound card. I don't know if my sound keeps going because I don't use my sound but my screen will freeze after about ten minutes of playing. It goes horizontal and it'll show two colors alternating all the way down. Any help would be great.