After a disk failure two weeks ago I had to resinstall Windows 2000 on my Dell server. This server is my domain controller and runs Exchange 2000 SP3. Ever since i did the reinstall theres been 3 times in 2 weeks where i have lost all services meaning users can't log in and exchange isn't functioning. I can't even shutdown properly logged in as administrator, it says "you do not have rights to perform this task". I end up having to do a hard shutdown. I am able to get to task manager and processor is only at 1-2 % utilized. The only thing in memory that seems odd is store.exe but after reading I guess it is normal for store.exe to take 1gig of ram. Any idea what could be causing this? Its not any certain time its gone 5 days once and one day another time. Anything I should looking for in the logs?