Bring up the SQL Server into single user mode and restore the master database.
<pre>From the command prompt find the folder that the sqlservr.exe is in and run it with the -c and -m switches. Leave the command prompt open as SQL Server is running in this window for now.</pre>
Then use the sp_dropserver / sp_addserver commands as if you were renaming the SQL Server.
<pre>exec sp_dropserver ‘OldServerName’
exec sp_addserver ‘NewServerName’, ‘local'</pre>
You can then restore the msdb database if needed. If all you have is a few jobs, just script them out and create them on the new server.