CPU 99% every other reboot post SP4

MSMDSRV.EXE 99% of CPU post Win2k SP4 – every other reboot.

I had a problem installing Win2k SP4. The service pack, errored at the end with the error: ‘Required .DLL not found. Setup failed to remove ISM.dll script mappings.’
Researching the error led me to IIS, where a
uninstall/reinstall of IIS was suggested, as IIS admin service was the one using the CPU. I uninstalled IIS, reapplied Win2k SP4 sucessfully, and reinstalled IIS.
BUT, now SQL OLAP service is taking all the CPU. The weird part is that it only takes the CPU on every other reboot. It seems like something is stuck in the registry or something.
Any help is truly appreciated.