File convertion question, specifically DRM protection?

Hello everyone,

Years back I used WMP to rip music that I legally purchased to my computer. I, at the time, didn’t have the forethought to see what format they were being ripped to. It turns out they were being ripped to .WMA with DRM (I believe) protection. I’ve done this with literally close to a hundred albums, and now am extremely worried I am not going to be able to use this music in iTunes (or pretty much any other software for that matter). How can I fix this and convert these files to MP3? I’ve done some research and so far have had no luck. I do not want to spend 40 bucks on software to do this as I think its ridiculous to pay to use the music I purchased LEGALLY in the way I want. So…. What can I do?

Thanks,
Joe