Do you know any DRM/Protected Music Converter that is Free?

I'd like to convert some of my protected wma music files to mp3 but all the software i've tried only give me a free trial and only convert a part of a song. I know that you could burn songs to CDs then rip them to get rid of the DRM but I prefer using a converter. Could anyone please suggest me a totally free protected converter that converts the whole song? Note that i've tried and didn't like:tunebite, tunebox, media-converter-wma-mp3 converter, youconvertit.com. Thanks in advance!