OK. I hope I'm beginning to grasp it now.
So the UPS I've got now is the following:
Brand - OptiUPS
Topology - Line Interactive
Automatic Voltage Regulation - Yes
Max Capacity - 1000VA / 700W
Battery - 7.2AH x 2
Surge Energy Rating - 1050 Joules

Not 100% sure I understand all of that, but I think it will do for what I need.

Yap, that's an Online Version. http://www.pcguide.com/ref/power/ext/ups/typesLineInt-c.html

So you don't need a stabilizer. For $150, it's cheap. It's around the same price in malaysia.

That should serve you fine for your setup. Unless you plan to do many power hungry things with the UPS (such as run your computer and monitor and refrigerator) you shouldn't go above the 700W that it can supply. And it will even out the power for you which will be better for your system.

~Viz

Well since the generator gets turned on in no more than 15 minutes after the power goes off, I'm going to try hooking up the monitor as well. Reading about this UPS in the manual, it's supposed to be for 4 regular desktops AND 4 17" monitors, at 10min backup time. The thing has 8 main power outlets on the back. So with my computer and monitor and inkjet and external hard disks all plugged in, i should at least be able to hit 15 or 20 minutes. It came without cables, so I haven't yet had the time to go back out and get them. My only worry about plugging all that in is if it will kick in instantly with the full power, or if the initial drain will make it flicker and consequently make the computer restart. But from what i understand that's not an issue with an online UPS... i do hope so.

UPS is suppose to give you more time during blackout to save your files and do a proper shutdown. The UPS won't pass it's QC if it will cause you computer to restart during blackout.

Anyway, you can do a test run, by going into bios and stay put. Time how long before the battery runs out. That's the closest you can get unless you want to risk some file corruption. Or you can boot using a LiveCD, and time the battery.

I figured it doesn't matter about the file corruption. Once more wouldn't hurt, it already goes off several times a day. On good power, it powers both computer and monitor for around 20 minutes. But I've ended up unplugging the monitor from the UPS, because the power is so dirty with extended brownouts, that there's constant strain on the UPS. It has a 10% buck/boost ratio. Only once has it stepped down the power for a few seconds, but more than half the time the boost is active. And like yesterday the power kept dipping below the 10% threshold, and constantly switched back and forth between line power and battery. Then when the power finally cut out completely, the UPS only lasted a minute. And after the power was back, it didn't have enough charge to start up just the computer--- had to leave it to charge for a couple minutes before the batteries had that initial power back. Kind of disappointing, but hopefully it will work with just the computer.

Wow, that's really bad. Lucky it didn't fried your pc before this. Intermittent power dip can sometime cause the switching power supply to goes hay wire and burn out.

Anyway, you can try look into power saving mode on your pc to lengthen the backup time. Try CPU throttling when idle. You can configure that in the BIOS. Also you can try shorten the time for your hdd to turn off when not active, in Power Options under control panel. Or down clock your pc if you don't need that much of processing power, like one of my friend did, so he can run the fan slower, thus less noise and power conservation. If you really need the processing power, then you can look for software overclocker, some motherboard does comes with one. So when the blackout comes, you can pull the slider and run in "lean mode" so it will last a bit longer.

If you don't plug in the monitor into the UPS, that means you'll not be able to work during blackout. Then you can configure the power button to trigger hibernate, Power Option in Control Panel. When blackout, just press the button, then it only need a minute or less to hibernate. After that the pc is completely off. One note though, if it happen to cutoff when you're returning from hibernation, you'll lose everything unsaved.

As long as I can get to the generator and turn it on within 10 minutes, I shouldn't have to worry about hibernation. The UPS has intelligent software stuff bundled, but can't use it currently because it communicates through a serial port and my motherboard (946) doesn't have one. I might look into software overclocking, because I do need the power. I've placed the UPS on a separate circuit now, and it seems to hold up a bit better. Wiring in the house is bad quality, in addition to low quality power coming into the house. So spreading out the load over a couple breakers is having a positive effect.

I've now run into a new problem: The UPS has a voltage window of 10% up or down. Beyond that, and it switches to battery. But much of the time the power is around 15% or 20% lower, and so the ups runs off the battery... if it goes on long enough it dies. If I unplug the computer from the ups and just plug it straight into the wall, the low voltage doesn't have any effect on the running of the computer, but then it defeats the purpose of having a ups. -- if a power cut comes then of course the computer goes off too. But I run so much off the battery with this low voltage. How can I avoid this? would putting a stabilizer before the ups offer any help? I would have thought so, but since this ups is supposed to contain its own stabilizer I'm not sure what it would do.

Your situation is a bit unusual here. In that case putting a stabilizer before the UPS will solve your problem.

The built in stabilizer is different from the stand alone stabilizer. Since you're using online UPS, the voltage stabilizing function is part of the design, so indirectly, the stabilizer is built in. Maybe the UPS portion is too sensitive.

Plugging your PC directly to the wall while during voltage fluctuation and it still works, is because the switching power supply has a wide working voltage range. Usually 180v to 260v for a 240v power supply, some less efficient one like those use in tv can cover from 80v to 260v. But the main purpose of a stabilizer is to reduce sudden fluctuation or voltage spike, which switching power supply cannot handle very well. Take note of the input voltage range of the stabilizer when you get one. Take one as wide as possible. Better still if you can try it out at the shop. Since most of the time the voltage is low, i believe it's the same at the shop as well. See if the stabilizer can work well. A stabilizer usually comes with a voltage meter or indicator, so you can monitor the output and see if it fluctuate. If it does, that means the voltage at your place is much lower that the stabilizer can handle, then you'll be out of option. So, let's hope not.

Sorry to give you wrong advice which didn't work very well before this.