svchost.exe gone crazy

Whee, trying to debug my mom's laptop. it's running maxed out constantly, having intermittent network connectivity. I did virus, spyware, and rootkit scans, and don't think I found anything (rootkit releaver found 9 items, but I think they are mostly leftover reg garbage from when my mom finally dumped aol as ISP). It seems like one of her svchost.exe's has gone nuts, often grabbing 99% CPU when an app tries to access the disk or network.

Thanks to a helpful, I discovered "tasklist /svc", so now I can see what services are in the svchost gone wild. Unfortunately, that's as far as I've figured out so far.