simple free midi app i can install on pc to test controller?

[eschertron]

I think this is what you're looking for...
MIDIOX

$50 for a commercial license is not exactly free.

[The Dude]

I believe there is a free version of Native Instruments Kontact. As I recall there were some limitations on the free version, but it might be good enough for testing purposes.

[bkahuna]

$50 for a commercial license is not exactly free.

There was no mention of it being a commercial application.
If it's someone working on their friends keyboard, I wouldn't call that commercial usage.

[bkahuna]

If you already have audio/midi recording software installed that supports vst plugins, you could use this Midi Monitor plugin: RS-MET.
If you don't already have a vst host, there are free ones available, but the learning curve is much steeper if you haven't dealt with hosted plugins before.

[eschertron]

There was no mention of it being a commercial application.
If it's someone working on their friends keyboard, I wouldn't call that commercial usage.

Yep. My bad.