Locate where it says File, then select the VOB files you want to turn into AVI, WMV, etc. After you have what you want, then on the right side, where you see "Output", you can select what format you want it in. The default is AVI, but you can change it to other formats, such as WMV. After that, just click Start, then it'll start reformatting.
When I used this, it does not slow down the computer, so you don't have to be offline while it's reformatting.
Note: It will, at least twice, pop up with a sign for you to Register. Click Later and you can move on just fine.