Might be the graphics card but it usually doesn't happen and I had only been playing for about 30 minutes.

By the way where do you see what kind of graphics card you have because I use my Dad's laptop and he can't remember what kind is in it. I looked in control panel and found this but 'm not sure that this is the right thing:
Intel(R) Graphics Media Accelerator Driver for Mobile Report
Report Date: 05/16/2008
Report Time[hr:mm:ss]: 22:47:59
Driver Version: 6.14.10.3943
Operating System: Windows NT* 5.1.2600 Service Pack 2
Default Language: English
DirectX* Version: 9.0
Physical Memory: 503 MB
Min. Graphics Memory: 8 MB
Max. Graphics Memory: 128 MB
Graphics Memory in use: 10 MB
Processor: x86 family 6 Model 13 Stepping 6
Processor Speed: 1695 MHZ
Vendor ID:
SATAN
Device ID: 0x2592
Device Revision: 3
* Output Devices Connected to Graphics Accelerator *
Active Notebook Displays:1
General Aetius
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