Windows 2000 Server gone crazy

Can someone help me with my Windows2000 Server.What happen is everyday between 2:00pm to 3:00pm my Windows 2000Server is un accesible at the network. What i notice is that all the installed devices are automaticcaly being unistalled & I am force to restart my server. Id check all logs & nothing seem to be are related to the downtime. I also check the scheuler if there is something scheduled to run at those time & nothing seem to appear. I also update my server to the lates patch & update the virus defenition but still nothing.

Thanks in Advance
Iskibanoyd