If you ripped with WMP, the default is WMA. There is an option to copy protect it. Why anyone would do it is beyond me. However, I don't remember it being a default. It wasn't the default on my computer and I've never used WMP for ripping. So my default settings had never changed from the first day I got my computer.

You might want to check your settings anyway. And while you're at it check the music files themselves. You didn't say which version you have. I have 11.0.6000.6344. To check your settings, go to tools, then options, then to the rip music tab. If copy protect is checked, you're kind of out of luck. There are programs that break the drm, but such discussion isn't allowed on the forums (sorry, can't even if it is music that you own). The "easiest" way is to burn to an audio cd then rip back onto your computer. Then you'll need to do some tag editing. If you've got everything from audio cds, you might as well rip them again. Painful, yes. But at least you won't lose any audio quality that would happen if you did the easy method. Just change your settings to mp3.

If they're not copy protected, I don't see why you can't convert them to mp3. You didn't mention which programs you tried. I've seen people around here mention CDEX and MediaMonkey. Since I have iPods, I use iTunes (this is rather bloated and a lot of people in this forum seem to hate it). I've used iTunes to convert unprotected wmas into mp3s (which can be done once the setting are changed to rip as mp3s). In iTunes, right click on the songs and select "convert selection to mp3." However, it actually makes an mp3 copy. The wma is still on the computer. I don't really recommend iTunes unless you have an iPod, but this is just an idea.

Good luck.