1. What is your system build?
2. What operating system are you running? XP SP1?
3. Have you tried unplugging the wacom device and starting it from there? apparently not
4. What error are you getting? 0x000000050 (page fault from non-paged file)
5. Do you still have your recovery disks? (???)
http://support.microsoft.com/kb/329293
That link should help you out a bit.
Seems you have your driver installed wrong or it somehow interfeared with your graphics driver.
Steps you might not have tried (on your own without any liability to myself or the Gaia community.)
1. Remove the Wacom USB and see if that works. Sometimes Windows hates booting with specific items attached.
2. Boot into safe mode with networking from the F8 option boot screen as shown in the link. Use device manager to find and uninstall the device. If not from there you can look up how to find your drivers and tinker yourself (DO NOT UNINSTALL ANYTHING YOU DO NOT RECOGNIZE)
3. Crying yourself to sleep
4. Windows recovery from disk (personally I hate this option)
5. Remove your video card if it's a desktop along with step 1. Turn it on without the video card. If it works uninstall the video driver and Wacom driver, plug both back in, reinstall. REMEMBER TO UNPLUG COMPUTER AND HAVE NO ELECTRICITY TO IT DURING THIS OPERATION.
5 is most likely overkill considering you got to the services page before the crash...