Thought this was a duplicated thread but its not.
Did you try any of the suggestions in this thread?
If the server is playing up Id go through all the event ID’s and address those first. You might find some false positives which MS acknowledge as FP’s, then start tracking what the machine is doing into the lead up to a freeze. Obviously check all drivers and the bios as well. Ive had windows servers run for weeks without any problem until a windows update forced a reboot, they should still be reliable. Memory leaks can be an issue but that can show quite quickly and I think there is a memory leak app checker around.