“Unexpected error occurred” during SQL Server 2005 SP1 install

We are seeing this issue for many customers installing SQL 2005 SP1.

Check out the resolution for it at our support blog

https://blogs.msdn.com/sqlblog/archive/2006/10/09/_1C20_Unexpected-error-occurred_1D20_-during-SQL-Server-2005-SP1-install_2E00_.aspx