Approximately two months ago, the day before our three week vacation, the power went out in the building. Only our file server was connected to an uninterruptible power supply (UPS). Not only did the all of the computers, with the exception of the file server, go down, but the network also went offline. Unfortunately the network would not reconnect on any of the computers after turning the computers and our networking equipment back on. In addition, an office computer would not turn on at all.
The fix for the network was simple. We rebooted the file server, and logged back onto the file server from each operatory workstation and the front desk computer. The dead office computer remains dead.
The lesson of the day is to connect each computer and all of your networking equipment (switches, router, internet gateway modem, etc) to it's own uninterruptible power supply. Unlike a simple power strip, uninterruptible power supplies will provide power to the connected equipment when the power cuts out. The length of time is dependent on the attached equipment's power draw and the UPS in use. UPS's generally get more expensive the larger internal battery they have. The length of time provided should be sufficient to ride out the power outage or turn off the computers safely.