Did you perhaps use some registry 'cleaner'? These are known to sometimes remove perfectly valid registry entries as well, with the result that the WMP Plus! installer can't determine where WMP is installed.
Please copy/paste the code below into Notepad, save it as a WMP.reg file, and double-click this file to add it to the registry. Can you install WMP Plus! now?
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\wmplayer.exe]
@=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,00,65,\
00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,4d,00,\
65,00,64,00,69,00,61,00,20,00,50,00,6c,00,61,00,79,00,65,00,72,00,5c,00,77,\
00,6d,00,70,00,6c,00,61,00,79,00,65,00,72,00,2e,00,65,00,78,00,65,00,00,00
"Path"=hex(2):25,00,50,00,72,00,6f,00,67,00,72,00,61,00,6d,00,46,00,69,00,6c,\
00,65,00,73,00,25,00,5c,00,57,00,69,00,6e,00,64,00,6f,00,77,00,73,00,20,00,\
4d,00,65,00,64,00,69,00,61,00,20,00,50,00,6c,00,61,00,79,00,65,00,72,00,00,\
00
Is there an easy way to convert to the 32 bit version so I can get WMP+ to load?
If you're running Windows 7 32-bit then you're always running the 32-bit version of WMP as well. It's not possible to run 64-bit programs on a 32-bit operating system.