Well, since they aren't part of the "windows package" you'll need to rinstall them. (I assume by 'reinstalled the computer' that you mean you reinstalled windows, right???) So, try going to the control panel and readding them. They apparently aren't listed in your registry, so you need to readd them...
Go to control panel > Fonts > File > Install New Fonts. Then browse to your C:\windows\fonts folder and just reselect them...