In general se face rebuild la master http://support.microsoft.com/kb/257716

Q. How do I rebuild the master database?

A: To rebuild the master database of a SQL Server 2000 instance, use the Rebuild Master Utility, Rebuildm.exe. You must rebuild the master database to fix corrupted master databases or to change collation settings for the instance. Detailed steps and information are available in the "How to rebuild the master database" topic in SQL Server Books Online. Also, be aware of the issue that is mentioned in the following article in the Microsoft Knowledge Base:

273572 (http://support.microsoft.com/kb/273572/) BUG: Rebuildm.exe utility stops responding when source directory is on a CD