I found out that The server was using all of its 4GB of RAM just before the SQL server service stopped. So I shut it down (it is virtual) added 4 GB of RAM to total 8GB. It has been running for 2 days now and not an error in the log.(touch wood) But I did notice that the serve did reach 4gb of RAM during the time that the outage usually occured.
So I continue to monitor and post results.
This has not fixed the problem. When I gave it 8 GB sql just used 8GB.
I dont know what else to try. Time for a SQL guru I think