The most POPULAR software for removing DRM protection:

WM RECORDER
the easiest audio/video stream ripper

WM CAPTURE - Super high quality on-screen video recorder.

SOUNDTAXI
remove DRM protection from Windows Media, iTunes music and video files

Other RECOMMENDED software and services:

• AUDIO/VIDEO STREAMING CAPTURE SUITE
  the best audio/video stream recording/capturing bundle
• REPLAY MUSIC
  the best streaming music recorder
  
  
• REPLAY MEDIA GUIDE
  free service to find and record online radio, Internet TV, podcasts
• AVS VIDEO TOOLS
  convert, split, join, remove commercials, edit, rotate, apply effects, capture, transfer, copy, rip and burn DVD and video files
• EMUSIC
  the best legal music download service
• AUDIBLE
  download audio books, audio magazines, newspapers, radio programs

5star freeTunes is a DRM removal software. It allows you to remove DRM protection from WMV, WMA, M4P, AAC files.

• Is it possible to remove DRM protection?
  This can be done with lossless DRM removal software or audio/video capturing software like 5star freeTunes. With 5star freeTunes you can convert WMV, M4P, MP4, WMA to MP3.
• How to remove drm protection from WMV, WMA, M4P, AAC with freeTunes?
  With 5star freeTunes it is very easy to copy protected music. It can remove copy protection of many different formats. Simply load the protected file and click on "Record". freeTunes then plays the file back to itself and re-records it anew, creating a fresh file free from DRM protection. Of course, the new files will still have all of the underlying information the old ones did, such as ID3 tags like Title and Artist.
• Can I convert DRM protected WMV, WMA, M4P or iTunes files?
  Yes, you can convert WMV, WMA, AAC, M4P files that are protected with Digital Rights Management (DRM).
• Is it illegal to convert DRM protected files with 5star freeTunes?
  It is illegal in some countries, while others allow to remove DRM protection. DRM removal software is intended to be used to make fair use backups only. Please don't abuse this rule.
• What DRM protected music formats does 5star freeTunes support?
  5star freeTunes supports DRM protected WMV, WMA from Windows Media Player and MP4 files from Apple iTunes store.
• Do I need media files with valid licenses before removing DRM?
  Nobody has cracked DRM for iTunes and Windows Media Player yet. You must have media files with valid licenses on your harddrive and you must be able to play the DRM protected files without restrictions.
• Can freeTunes convert DRM protected video files to videos without DRM protection?
  freeTunes can convert DRM-protected videos to audio files only.
• Why should I remove DRM protection?
  First of all, because when you can't transfer legally purchased music and videos to your iPod, Sony PSP, Microsoft Zune or any other player because of the DRM protection, you can't convert DRM protected files to the format you need before removing DRM protection.
  
  Also many service providers are not as reliable as Apple's iTunes Music Store. They can disappear some day and you won't be able to re-acquire your licenses.