To my knowledge, you cannot access the files anymore. The files are locked using a key generated off your hardware profile. That might make you think that it should be immutable as long as your hardware stays the same, but unfortunately, that isn't the case. You can also reset your DRM key... but I think that requires Windows Media Player 11 or lower. I actually had to do that once as something happened with it, and I couldn't watch any protected TV channels. So, I either had to sacrifice all of my protected recordings or never be able to watch more again. :\
...anyone tell me why we really want to keep this software?