I have had this problem on win xp and 2000 which is what i have now with the same problem, the closest thing i have found for a fix is a program called processxp from www.sysinternals.com that will show the child programs of svchost and u can close the one that shows high % but since u closed svchost some stuff doesnt work right i have noticed periodic internet activity problems and some other stuff acts funny.pretty funny as a matter of fact but its better than 100% cpu usage. Something i just tried but im not sure is going to work is with that program u can open the child svchost program and it shows all the threads and their cpu usage then close the high % ones there. That way svchost is still working but u stopped the problem thread, mine was a remote procedure call which sounds like blaster but ive tried all the removals and patches.(the threads popped up 1 more time after i closed em but they havent come back for a while now) its been working good for about 20 mins on the net now (which is when mine happens too, never offline).Ill let u know if it keeps working after a day or so. hope it helps you.

I have had this problem for ever and it is very annoying and i think i might have finally fixed it, of course ive thought that about 20 times