SQL should run under a non-administrative account. It's a security best practice.
Create a domain account for SQL. I would suggest that you se the domain account so that it does not allow interactive login. Make sure that the account has full control over the directories that have your data and log files in, and also the directories that the backups go. Change the SQL service account using the SQL Server Configuration Manager. That tool will ensure that the new login has the permissions that the SQl Service needs.
Do not make it a local administrator on the server.
We've been able to solve this by adding a non-administrative user (SvcUser, if you will) to the Security tab on the executable properties page, giving this user full-control, and also giving this user sysadmin (via sp_addsrvrolemember) role in the database.
That's not what I would call a non-administrative user. By adding it to the sysadmin role, you've given that account full system administrator permissions to the SQL instance. Doe the account really need that?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability