If you are having the RPC rebooting problem, your computer HAS been compromised by a worm/virus/trojan or whatever you want to call it.

Run a full virus scan and/or post a HijackThis LOg. Some are new enough that AV's are not picking them up as of yet.

If you have come for help please always include a copy/paste of a recent HijackThis Scanlog to help us assist you.

http://www.tomcoyote.org/hjt/

And most important, when all is done you are advised to change any critical passwords, especially financial ones.
Some of these are "keylogger" trojans and what you have been typing may be logged to a text file on the drive and accessible to a hacker. This is often keylog.txt in a Windows directory, but may be named something else.

PS..most people are having no luck with repair install, but system restore IS apparently effective.

additional info from symantec

http://securityresponse.symantec.com/avcenter/venc/data/w32.blaster.worm.html

That reminds me, system restore should be disabled, reboot and then reenabled after exploit is fixed.

W32.Blaster.Worm Removal Tool

http://securityresponse.symantec.com/avcenter/venc/data/w32.blaster.worm.removal.tool.html