Starting with Windows XP SP2, Windows Server 2003 SP1, and Windows 2000 SP4 with MS04-012: Cumulative Update for Microsoft RPC/DCOM, RPCSS no longer caches certain COM class information from the registry, so that registry key handles are closed as soon as possible to prevent possible data loss.
You may experience a CPU utilization increase in the RPCSS instance of the svchost.exe process caused by the need to read the registry values every time they are needed.
If you are willing to risk possible data loss, you can use REG.EXE, built into Windows XP and Windows Server 2003, or from the Windows 2000 Support Tools, to run the following command:
REG ADD HKLM\SOFTWARE\Microsoft\Ole /V EnableCatalogCachingForBaseCOM /T REG_DWORD /F /D 1
ORREG ADD \\NetBIOSComputerName\HKLM\SOFTWARE\Microsoft\Ole /V EnableCatalogCachingForBaseCOM /T REG_DWORD /F /D 1
NOTE: A different issue is described at FIX: COM+ applications may consume more CPU resources after you apply the MS04-012 security update to a computer that is running Windows 2000 Server or Windows 2000 Professional.