There's nothing in the software which will keep your battery from charging. To test this, you can turn the laptop off so no software is running at all.. Does it charge?
Basically, if it isn't charging in Windows, it probably won't charge shut off either. This points to a hardware problem. What happened exactly? I have no idea, but it is probably coincidental that it happened along with your Windows installation.
Some ideas on what this can be is (most likely) a burned out AC power supply. My second guess would be a broken power jack (that little hole the AC fits into can get lose or broken very easily). And my third guess would be a board problem (I've actually see a Dell 600M - almost identical laptop - with the exact same problem).
If you can swap out the power supply with another, you can rule out the AC adapter. Maybe a friend has a simliar Dell laptop or you can buy a universal one and take it back.. hehe!
Test for a broken power jack? Not quite so easy, but if your new or borrowed AC power supply doesn't work, then it is definitely a good chance. You might notice the pin inside the barrel hole wiggles a lot... or maybe isn't even there anymore. Or perhaps when you wiggle the end of your AC supply the power intermittently cuts in/out. These are good signs you'll need to have this taken to a professional to get fixed.
And the board would be the last result, assuming at least one of the batteries are good. In this case, you'll proably want to send it back to Dell (if possible) or get a replacement board from a place like eBay and cross your fingers.
