Audio files - Windows explorer needs to close

Here's a weird one. I'm running Windows XP Pro (SP2), and use an audio player called Quintessential Player. At some point in recent weeks - I can't be sure when - all the audio files on my machine (wav's, wma's, mp3's) seem to have acquired the following annoying characteristics:
1. they have all taken on the icon associated with Quintessential, even though I did not set up this as the default file association. Any attempt to re-associate these file types (with Windows Media Player for example) seems not to work.
2. Attempting to right-click any file with this icon in Windows Explorer (for instance to get the properties or perform some other operation) brings up the error message "Windows Explorer needs to close - sorry for the inconvenience.... " etc. Windows Explorer then duly shuts down; when you bring it back up, there are several icons missing from the system tray (i.e running tasks/processes have closed - this is normally what happens if Windows Explorer crashes).

I've tried doing a System Restore - no effect. Any views on causes? Other courses of action I'm thinking of are de-installing the Quintessential software, or attempting to make clean copies of all the files, or perhaps run them through an audio processing program - however, as I have rather lot of audio files, this would take forever.

 

De install the audio player, and try winamp.

http://www.winamp.com/

Free version runs every audio format, also streaming radio, the pro version (not free) has some more options, but for a player you dont need the pro version. With free plugins, you can also do file conversions.

If the problem remains, make a crashdump file. There are people around here who can read this.