The easiest way to play .RM files on Windows is to install
RealMediaSplitter 1.0.1.0 which can be found
here at SourceForge.net.
Just
- put RealMediaSplitter.ax (324kb) from the zipfile into (e.g.) the WINDOWS directory,
- open a dosbox there,
- type "regsvr32.exe RealMediaSplitter.ax".
Now any DirectShow capable program like MediaPlayer can open .RM/.RA files directly

! Much better than installing RealPlayer or reencoding to .MP3 i reckon.
Especially RealPlayer bothers me! Asking for your email address before downloading; Installing 11MB of unnecessary crap; registering loads of filetypes which no one uses and only slows down Windows Explorer; trying to access the internet behind your back; REAL-ly not my thing..