Blue Screen Error Help, Please

When I turned on my laptop I got this blue screen with:
A problem has been detected and windows has been shut down to prevent damage to your computer.

BAD_POOLER_CALLER

Check to make sure any ew hardware or software is properly installed. If this is a new installation, ask your hardware or software mfg. for any windows updates you might need.

If problems continues, disable or remove any newly installed hardware or software. Disable BIOS memory options such as caching or shadowing. If you need to use Safe Mode to remove ordisanle components, restart your computer, press F8 to select Advanced Startup Options, and then select Safe Mode.

Technical Information:
*** STOP: 0x000000c2 (0x00000007, 0x00000CD4, 0xF6A611EO, 0xF7610050)

*** ati2mtag.sys - Address F6A611E0 bast at F698E000, DateStamp 4473bfaa

Beginning dump of physical memory
Physical memory dump complete.
Contact your system administrator or tech. support group for further assistance.

This is the laptop that we use to homeschool on, so a lot of our material is on it.

What do I do, hopefully that's not too expensive.