I'll bet Peter lightened it up quite a bit too. There are a few ways to do it, and do it very quickly. Best bet is to get Scott Kelby's book for Photoshop Elements, I was just using mine for CS tonight with yet another situation. His books won't teach you the hows and whys, but will get the job done quickly.

Image > Adjust > Levels and also Image > Adjust > Curves are two very powerful tools in Photoshop.

Idea #1: Wouldn't have mattered for the amount of exposure. It would give you a faster shutter speed for the same aperture; or a smaller aperture for the same shutter speed. Can be handy for low light and/or moving subjects - but it wouldn't change the amount of exposure if you're in an auto mode.

Idea #2: The camera's light meter is always looking for an overall midtone and usually works well. When you have a lot of white snow, you'll probably need some "+" compensation but 1-2/3 stops sounds a bit much. Varies from camera to camera and if you were using film it would have depended on whether it was slide or negative film. Usually 1 stop gets it done, but YMMV.

Idea #3: Exposure is made up of three things. Remember algebra?! It's an equation! ;) The three values are ISO speed, aperture and shutter speed. If you move one value by a stop and no others, you'll get one stop more or less exposure. If you increase one and decrease another, the net result is the same. Aperture doesn't stop motion, it's just shutter speed. You may need to use a larger aperture (or higher ISO speed) to get that higher shutter speed though. For what you've got here, 1/100 should be OK.