It's unfortunate that you can get flat batteries right out of the package. I buy them around 25 or so at a time, and sometimes they just don't work properly. As a bonus, my glucometer takes CR2032's, very handy. I put some maxells in a couple months ago, and have had a lot of problems with them. Just changed for some Panasonic batteries, worked first try, but have to see how long they last now.
So, if you don't have another battery to try, then test the DC voltage with a multi-meter, see if it's down a bit.
It is the usual issue when a computer doesn't keep the correct time, but should also check the bios, see what the time is doing there, set it to the correct time. Load windows and set that to the correct time, then if windows goes wrong again, recheck the bios and see if it did too. If the bios stays correct, the battery is fine, and it's a windows issue of some sort.