SvcHost.exe using 100% CPU (processor) on a Windows XP SP2 machine:
Running “Tasklist /Svc” from a command line will show the instances of SvcHost.exe and what is running under each instance of SvcHost.exe (there should be about 5 instances of SvcHost.exe running on an XP SP2 machine).
You can go into the Registry and see all the things running under SvcHost.exe by looking in HKEY_LOCAL_MACHINE\ SOFTWARE\ Microsoft\ Windows NT\ CurrentVersion\ SvcHost .
The way I found and fixed this problem was by downloading Process Explorer (from SysInternals, which is now owned by Microsoft). It showed me that WuAuClt.exe was running under the instance of SvcHost.exe that was gobbling up my entire processor. WuAuClt.exe is the Windows Update Automatic Update Client.
After doing some web searching, I found that in many cases the problem is because of Microsoft Update (Microsoft Update handles all MS products, whereas Windows Update handles only the Windows OS). To turn off Microsoft Update, go to http://windowsupdate.microsoft.com, choose “Change settings” on the left hand side of the page, then at the bottom of the page choose “Disable Microsoft Update”.
Please also look at MS KB article KB916089 for some related information that may be helpful. I downloaded this hot fix and it made no difference on my system.