I'm new to this forum, but an electronics tech of 44 years, so grounding is nothing new to me.
A big problem I see often is that people will NOT plug their entire computer system into the same outlet. That's a absolute MUST!
Everything that touches your computer tower, electrically, should be plugged into the UPS and it should be plugged into a three pronged wall outlet.
That will keep everything on your system at the same polarity and grounding potential.
If the computer system is properly grounded and you have static on your body, like from a wool rug, the static will find its way to ground thru your computer. Do something about your own static in that case.
Where I live, here in Florida, static is NO problem, but when I lived up North, static was a huge problem in the winter.
But, static or no static, it's still advisable to keep your whole system plugged into a common circuit.