I thought fraps saved as jpeg. What does it save as, then?
no, the free version of fraps saves in .bmp, which need to be converted to .jpg. Only the not free version saves in jpeg.

however RTW has a screenshot button whihc saves screeenshots in the .tga format.

In order to open this file format and to convert it to jpeg i suggest using irfan view. It is free, small and can open any picture format that exists.

http://www.irfanview.de/