[BluffTHIS!]

Plugging a UPS into an ungrounded outlet isn't going to ground anything, though there are good reasons to use a UPS anyway. I assume you actuall have two prong outlets and not 3 prong without grounding. I seem to remember old type of outlet adaptors with a small metal ring protruding from them. If you plugged one of those in and then ran a wire to plumbing pipe, which is usually grounded, then that would provide grounding and you could then plug an outlet strip for your computer into that adapter. You can get an outlet tester to verify whether that ground wire is indeed providing grounding.