I had the same issue on my servers. Using remote desktop I tried to reinstall the client but I got errors about permissions to remove the services during the uninstall. After poking around for a while with logs I decided to logon to the server's remote console ("Mstsc /v:servername /console" at the command prompt) and I found an error message that did not show on the remote desktop. I clicked the ok to clear the error message and I am currently backing up my sql dbs on that server.
Hope that helps!
Message Edited by Paul Jamieson on 05-08-200808:11 PM