Overheating can also cause BSoDs. See My PC Shuts Itself Off Mid-Boot, even if your PC is not shutting itself off mid-boot, for advise on cooling your computer.
If nothing else works, try updating your drivers. Click Start (Start, then Run in XP), type devmgmt.msc, and press ENTER. Double-click a device, click the Driver tab, and select Update Driver. If Windows tells you that you have the most up-to-date driver, don't believe it. Windows is also displaying the name of the device, and the driver's version number and date (all underlined in red, below), so you can easily search the web for a more up-to-date driver.
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