|I do not know where to even begin with so many myths and rumors.|
The power supply's job is to make electrically anomalies irrelevant to the disk drive. Anything a UPS might do (except the power backup function) is already inside every computer power supply. Incandescent bulbs can dim to 50% intensity and the computer must still work perfectly normal. Why? That is what the supply does - make AC mains variations irrelevant.
If AC mains voltage drops even lower (bulbs dim less than 40% intensity), then the UPS does something useful. It provides temporary (and very dirty) power. Dirty? Of course. Power often so dirty as to be harmful to small electric motors and power strip protectors. But again, that is what the supply does. Make even dirtiest power from a UPS completely irrelevant.
AC receptacle tester will not report anything useful to your problem. It may find other problems. But again, circuits inside power supplies make those problems irrelevant.
Memory tester is also irrelevant. If memory was defective, the OS saw the problem, worked around it, and stored error messages in the system event logs. But you wiped the disk drive. Important history messages (relevant to your failure) destroyed.
Now you are confused by the BIOS, Windows, and hardware. A well understood diagnostic procedure breaks a problem down into parts. Then solves each part one at a time. In your case, stop working with or using Windows or the BIOS. Your computer manufacturer (if the fewer more responsible ones) provides a comprehensive hardware diagnostic for free on the CD or from their web site. If yours is not so responsible, then download the disk drive manufacturer's diagnostic from their web site or from the Ultimate Boot CD web site.
Simply work with what is known bad. And do so only with software designed to find problems - not mask them (as Windows is designed to do). That is a diagnostic that boots from a CD (that your burn) or a memory stick (or floppy if you still have one).
Without facts, other are doing the 'try this and fix that only on wild speculation' technique.
Just because someone uses a computer or programs one does not mean he knows anything about hardware or electric power. Good diagnostics means break a problem down into parts - then learn what is bad. First you must learn what the defect is before trying to fix anything.
Power is only a problem if your power supply was a crappy type dumped into the computer assembler market - that is missing essential functions that make power variations irrelevant. Even that APC recommendation does not claim to solve those power problems - despite popular myths that say otherwise. (IOW view manufacturer spec numbers to learn what it really does).
Nobody can provide anything (but wild speculation) without facts from that diagnostic. First establish hardware is good. Only then move on to other suspects such as the BIOS or how Windows is being installed. Solutions are (as they say in CSI), "Follow the evidence". Start with diagnostics to first learn what you have. Solution come later.