Full Factory Restore

Hello, I have a Gateway Notebook Laptop model MX7515. I've had it since 2005 and for some reason it lost its sound drivers recently and I have been unable to download new ones or recover the old ones. It will not uninstall games, and it will not restore to previous dates. I have the Windows XP recovery disk, but it will not run it, even with putting the CD drive at the top of the Boot list in BIOS. I've tried pressing the F11 hotkey during startup to bring up the system recovery options. During the process it gives me a blue screen and a message that says as follows: "STOP: c0000221 {Bad Image Checksum} The image shell32.dll is possibly corrupt. The header checksum does not match the computed checksum." Then from there I have to hold down the power button to do a hard shutdown since the computer is frozen from that point forward. Any suggestions? Thank you