Updating from a previous version of MP3ext.

It doesn't matter, when you just overwrite the old version; but it leaves some
unused files, reg-entries, when updating. But isn't this a common problem with
all windows-programs? Well, if it doesn't bother you, you can go on with
installing the new version, and skip the rest of this test.

If you have installed MP3ext before, then you should uninstall it before,
since I use other places for my DLL now. The new DLL will not uninstall all
the keys added by the previous versions, since it uses a different method for
adding the page to the registry.

The only problem is, the old inf-file used for installing has a bug in its
uninstallation: it removes the association of .MP3s!
You can fix this by removing the following line from the inf-file
(windows\system\shellext\mp3ext.inf):
HKCR,.MP3,,2,%MP3Player1%

now the uninstall works correct.