I am having a similar problem. Recently one of the SVCHost.exe processes has been hogging the CPU using as much as 93% on the CPU processes on a periodic basis with a period of 5 to 10 seconds. Needless to say, the system slows considerably. Using M/S Process Explorer to trouble shoot, I found that the specific SVCHost.exe that if hogging the CPU cycles is handling 26 services including: AudioSVC, Browser, CryptSVC, Dhcp, ERSVC, EventSystem, helpSVC, lanmanserver, LanManWorkStation, Netman, Nla, RasMan, Schedule, Seclogon, SENS, SharedAccess, srservice, TAPiSrv, Themes, TrKWks, W32Time, winmgmt, Wscsvc, wuauserv, WZCSVC and ShellHWDetection. While troubleshooting (and trying to understand what was happening with these various services) I found that if I "Paused" and then "Resumed" the ShellHWDetection service, the problem disappeared -- that is the SVCHost process settled down to using less that 2% of the CPU cycles for the remainder of the time that the computer was on. However when I restarted Windows, the problem reappeared. Since the ShellHWDetection service provides notification (presumably to the OS) for Autoplay hardware events, it appears the service is quering or waiting for some notification from a hardware device and that the query is interrupted by pausing the service. Is there anyway I can find out what's going on?