The Configuration Manager Service Pack Install Guide
This document was created to help in troubleshooting Configuration Manager Service Pack 2 (SP2) install failures. This document is not entirely specific to Service Pack 2 and can apply to Service Pack 1 installs, upgrades from SMS 2003 to SCCM, and future service pack or Configuration Manager versions that rely on .mof file compilations, SQL SPNS, provider DLLs, etc.
The Configuration Manager Support Team Blog : The Configuration Manager Service Pack Install Guide