2005 SP2 Install Failed, And Now SQL Server Is Unusable.

Hi,

I have a problem with my SQL Server 2005 instance after trying to install SP2.

My machine has a default instance of SQL server 2005, and 2 instances of SQL 2005 express.

I installed Express SP2 and this installed without a hitch.

Then I installed SP2 for SQL Server 2005. After the install, all the components had installed correctly except the Database Engine, which had a status of failed. I did not investigate why, I simply re-ran the install.

It failed again, so I investigated further and I found out it failed because it had not been able to start the service VSS Writer. I looked at the service, and found I had changed the user which gives the service rights to start. I changed this back to Local System so the service could start correctly.

I then re-ran the SP2 install. This time it failed in a different place. The reason this time was my user was not a valid user for my server. This is a first, because I logged onto the database using this user name minutes before running the install. The install must have deleted my user. Then I tried to login using the sa account only for my server telling me that the sa account has been disabled.

I now cannot log into my database at all, and am stuck. If I try to rerun the install it tells me it cannot connect to the server to perform the update because there is no user.

Please Help!