The computer has rebooted from a bugcheck. Plz help!

Hey there!

I'm having some nightmares here! My notebook is rebooting quite often and I have 2 minidumps files. I would like if anybody could tell me whats the problem.

I got this message once at reboot:
BCCode : 9c BCP1 : 00000000 BCP2 : 8053FAF0 BCP3 : A2000000
BCP4 : 84010400 OSVer : 5_1_2600 SP : 1_0 Product : 768_1

C:\WINDOWS\Minidump\Mini112606-01.dmp
C:\DOCUME~1\User\LOCALS~1\Temp\WER1.tmp.dir00\sysdata.xml


Thank you very much!!