Yeah, I'm pasting this from the last post just incase you didn't see it:
Its not listed in the windows components either in this computer, so it might not be on yours...
so try this:
Hard delete the program (its stored in a different place on this machine, though should be in:
C:\Windows, (i'd think).
If not, run Windows Search in safemode if it works, and search for files and folders from safe mode, and search for 'wordpad.exe' and then delete the program which is a complex way of doing it, but seems the only way, and if it fixes your problem, then good! Though hopefully its in a simple place like that, so you don't have to, espiecally if safemode won't work it.
Its weird though its choosing programs to work with and others not too... that makes me think its a bug, though the online scanners didn't find anything.
I hope this suggestion helps, and it's my last straw apart from a full re-install i'm afriad, so I hope it fixes it