I have a SQL Server 2008 R1 server where sometimes the CPU is maxed out. When this happens I can't connect to the DB Engine. I can't even get into SQL Configuration Manager. I have to go into Services and stop the SQL Server service manually. After SQL is restarted, everything goes back to normal.
I have the SQL Server memory to only consume 3GB out of the 6GM of RAM that is on the server.
What should I check in order to find what is causing the CPU to max out?