I've been using DAWs for a long time and just set up Reaper on a new dedicated Win7 32 bit machine. I'm having trouble with Midi input, but can use my MAudio Keystation 88 Midi only keyboard with a midi to USB adapter.. The cheap type that only has one in and one out. The problem I'm having is that no matter which VST I chose, be it a B3, string synthesizer, or Sampletank, not only do I get the appropriate sound produced by the VST, but I always get a simple piano tone as well. The piano not only plays, but it records as well. When I replay the midi recording, I get the piano tone along with the VST sounds. For example, if you've heard the VST 'piano and strings', that's what it sounds like. The keyboard is a midi only unit. It can't produce sounds on its own. I think it may have something to do with a generic GM Midi being triggered along with the particular VST. Anyone ever deal with this..or had it happen to them?

Would this have anything to do with windows built in midi thing being enabled? I forget what it's called and I'm on my ipad right now. Sounds like it's playing through another midi engine as well as reaper, but I might be way off.

Hi. Not had this happen but you could try altering the "MIDI MUSIC PLAYBACK" option in the Sounds and Audio Devices in the Control Panel. Are you using the pc'c onboard audio BTW? Do you get the same problem with an external sound card?

Problem VST plays piano 'and' any other instrument I chose - Fixed 

For some reason, my DAW had reverted to the standard Wavetable, which I presume has a built in GM midi table. And Asio4All had screwed up, so was no longer available as an input or output choice. I reloaded ASIO4All and chose that for input/output and voila! Not only did the annoying piano sound disappear, but my latency issues did as well. Thanks for the replies above! ;-)