Ok, in that case (0%, 0sec) it's probably a stuck rollback (they happen from time to time, it'll be trying to get something that it can't get) and it's usually safe to restart SQL. Do it next time you have a maintenance window, unless this rolling back session is causing problems.
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