If you had a previous version of pyro, you may receive this error message in the Help>About window, or when you try to activate the MP3 encoder. You will need to do a "clean Reinstall" of Pyro 2003 to rectify this situation. Here is how
 

1. Click START > Settings > Control Panel> Add/Remove Programs. Locate pyro 2003 in your list of installed programs and uninstall it.
2. Click START > Run and then type regedit in the box.  Click OK
3. You will now need to delete two Registry Keys. DO NOT DELETE ANY OTHER KEYS. Click the + sign next to HKEY_CURRENT_USER. Then click the + next to Software. Then click the + next to Cakewalk Music Software. Then select the Cakewalk pyro Registry Key and Delete it 
4. Click the + sign next to HKEY_LOCAL_MACHINE. Click the + sign next to Software. Click the + sign next to Cakewalk Music Software. FinallySelect the Cakewalk pyro Registry key and delete it 
5. Restart your Computer, and reinstall pyro 2003