I realized today that I might have something to offer this topic. Last week, my Sims were being weird on the Main Menu screen and I figured out how to take pictures of my screen without any help from my husband! I'm a little proud of myself.
I googled how to take pictures of my computer screen and was given the PrtScn key solution, but I couldn't get it to work. Further research brought me to something called "Snipping Tool". Our PC runs Vista and this program is found under All Programs>Accessories. To use it, you need to be on the screen you want to take the picture of, with your game in Window Mode. Then, hit the Start Menu>All Programs>Accessories>Snipping Tool. It opens a little box and allows you to drag your cursor creating a box around what you want to take a picture of. Then it automatically puts the picture into the box the program opened, here you can edit the picture and save it in the format you want, to the folder you want. It is super easy to use!
I don't know if Windows 7 has a similar tool but it's definitely worth checking out!