stop error 0x0000008E

Windows will not start.  I am getting the following message: 

STOP: 0x0000008E (0xC0000005, 0xBF839706, 0xF7E94668, 0x00000000)

win32k.sys - address BF839706 base at BF800000, datestamp 3f73195d

events leading up to this...

Last night the system was running slow and freezing up. I shut down windows.  I got a message that rundll32.exe was not responding.  I hit the "end task" button. Windows shutdown, I restarted.  Things still weren't right so I have repeated these steps over and over - each time getting the same error for rundll32.exe.  Internet explorer stopped working - though i still had broadband connection, because aol was working.  calling up the control panel was taking about a 90 second delay.

Finally i downloaded/installed the windows XP service pack from the microsoft site.  this required that i restart windows.  i shutdown windows, and now it won't come back.  (I am on another computer writing this.)

i have tried F2 setup to startup in "safe mode" and a long list of things scroll by until it pauses at windows\system32\drivers\agp440.sys.  then the screen goes blue and says:

STOP: c000021a {fatal system error} the windows logon process system process terminated unexpectedly with a status of 0x00000080 (0x00000000 0x00000000).  the system has been shut down.

Please help me!!!!