I have a Small Business 2008 server in a small office (8 people) running Domain Controller, DNS, DHCP, File Server, Exchange Server, Blackberry Enterprise Server Express 5.0, Hamachi (VPN), and LogMeIn (Remote Access). The Hardware is all Intel (Case/Power Supply, Processor, Motherboard.) and is running RAID 1 for OS and another RAID 1 for Data drives off the motherboard.
What happens is that every so often (1-2 times a week) at random times users will be unable to access the server shares, email, dns, etc. When the server is check it will be displaying lock screen (ctrl+alt+del to login) and sound for all the world like it is on. If ctrl+alt+del is pressed there is no response. RDP errors out saying it cant locate the target. Server has to be hard rebooted and will start working again when it comes back up. Looking over the error logs there will be no errors, the only sign of a problem is that event viewer will stop recording events when this happens (i.e. If the server goes down at 10:00AM Sunday and is rebooted at 8:00AM Monday there will be no events in the error log from 10:00AM Sunday - 8:00AM Monday.
This has been going on for a while now and is getting extremely irritating, I have replaced the ram and it is still doing the same thing. HELP!