Installing SQL2005 SP1 - checking for locked files via Windows Installer file sqlrun_sql.msp

Please note that you have to shutdown all the services except SQL Server service, before you start SP1 installation.

When I tried to install SP1 yesterday I came across a small problem. I had all SQL related services shutdown, except SQL Server service (It is required to run when SP1 installation starts - Installation process will shut SQL Server service later on during installation). I came across this problem. During Database Services, installation process hung stating the following message.

checking for locked files via Windows Installer file sqlrun_sql.msp

I tried few things and couldn't get it to work.

Eventually I moved all the user created database files (MDF and LDF) to a different directory from SQL Data directory (in my case - C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data) to a temp directory.

Then I re-installed SP1 and it went through without any problems.

Thanks
Sutha