I've got a last resort for you. I've lived in a couple houses with no grounded outlets. I plug my UPS into one of those 3 prong adapters then run a #12 wire from that loop that's on the adapter to a water pipe. This will not guarantee a ground but it's your best best. If you're on or near the ground floor run it out a window to an outside pipe or drive a metal spike into the ground and connect to that. I once used a metal coat hanger as a rod and it was sufficient enough to ground a trailer. I stopped melting extension cords.

The reason I say a water pipe will not be a guarantee is because if there's plastic pipe anywhere in the line it will break the circuit. Hot water pipe might be best as the water heater will definitely be grounded. A cold water line is the typical ground point but it's more likely to have plastic from repairs.

"Ground" literally means that circuit is connected to the ground somewhere. If you are in something like a basement apartment in a house look in the flower bed outside for an existing ground rod. Quite often you'll find them near telephone / cable TV hookups.

I have lived a year in my current place where I have not had grounded plugs or the option of running my own ground and I've already lost one hard drive to a simple power outage.