For my 50th last October my wife gave me an M-Audio Keystation 61es MIDI keyboard controller because I want to seriously learn to play the piano. A trumpet or french horn (my former main instruments) are out of the question because of my maw-in-law's heart condition. I had a nice Kawai keyboard back in the mid-80s but finally sold it because I never had time to play.
At first I was using Magix MusicMaker, a loop-based music program, but in order to hear any sound I had to use an ASIO driver which disables any other sound sources.
After 6 weeks or so, when I bought my first lesson set, I stumbled across VSTHost which uses the normal Windows sound driver so I could listen to/watch the video and immediately play along. Don't know why but a week or so ago, the little program stopped working. 
I removed it from my computer, d/l'd it again, "installed" it again (it's kinda like DOS...there's no "installation" per se..just a small executable. It's all about remembering where you put it and the VST plug-ins) but I still can't get it to work! I know the correct Windows sound driver is loaded because I can hear sounds. I've pored over the documentation for VSTHost but I've found nothing to remedy the problem.
Do you know of any other free programs/utilities that will run VST plugins? Or what could suddenly cause VSTHost to stop working. I'm not really looking at mixing, mastering and recording (not necessarily in that order) yet. I just want to be able to hear myself play what I can already play and work on my technique. As an aside, I'm just about ready to re-install W7 due to DVD Shrink's & Decrypter's sudden decision to look for Nero which isn't even installed! But that took place after I installed Quicktime. My piano troubles pre-dates that issue,, unless of course this is all part of the same problem.
Thanks for any help you can share!
Jack