We have been having problems with one of our servers rebooting on it's own and understood that SP1 was supposed to fix this problem. However, when I downloaded and installed the sp and rebooted the server it got all the way to the Windows splash screen and went no further. I let the server sit for 30 minutes before I turned it off. The only way I could get it to come up was if I booted into safe mode and uninstalled SP1. Does anyone know of any issues with SP1 that may cause this to happen? Thanks

Sp1 is too new, never install a SP this soon. Remember NT4 SP6...

Installing a Service Pack that corrects a problem you're facing is not a bad idea in my book. My problem though is where did you hear this? Is this documented by Microsoft? Before installing SP1, did you check your event logs? Was the server in a verified working condition with no problems other than this issue? Did you verify this is related to what SP1 fixed? Server rebooting could be a hardware problem for example, which could also be causing these issues with SP1 installs. "Republicans in Congress are moving to ratify a constitutional amendment to ban flag burning, thus ending the Iraq insurgency."

According to the event log the problem of rebooting was being caused by Lsass.exe. Now before you start thinking virus that's not the case. We have scanned this thing so many times with several different programs and none have found a virus. And yes this is supposed to be a documented problem that SP1 fixes. But check this out. We have an identical server that we are really not using now. Both servers have Lacie external firewire drives connected. The server we don't use has sp1 and hangs on boot the same as the other server until you diconnect the external drives. We can reconnect the drives using USB and it works fine. So now I wonder if SP1 is affecting our firewire drivers.

Check for BIOS/firmware upgrades for the servers. "Republicans in Congress are moving to ratify a constitutional amendment to ban flag burning, thus ending the Iraq insurgency."

Believe it or not it was the BIOS/firmware on the external hard drives that had to be updated. And we had to make sure they were connected via FireWire in order for the update to work. If they were connected via USB they wouldn't even update. Thanks everyone I really appreciate it.