There are software pianos such as Pianoteq who also offer a free download which plays fine in the key of C. Playing in other keys won't work out because some of them have been blocked in the demonstration version.
This list also mentions most of the main virtual pianos: http://www.keyboardmag.com/article/ulti ... t-08/87255
A short while back I downloaded the free trial of Pianoteq.ennogs wrote:Can somebody please recommend me a really easy to use midi keyboard software program for Windows 7. It would be great if I could also record my own sounds and get the keyboard to play them.
I thought it was really good, and although there are a few notes disabled I didn't find it particularly annoying to play in any key, in fact it was a very interesting experience. After 20mins the program stops functioning, but restarting again immediately from the interface is simple. At 249€ (213 pounds) for the standard version, you may or may not think this worth purchasing.
Interesting to note that there's also a cut down version called Play which includes the same instruments, sounds and playability as in the Standard and Pro version, which at 99€ (85 pounds) imho is a great deal.
I reckon playing a software piano opens up a whole new dimension and stimulates the need to keep at the keyboard. Oh, and even the free download enables you to record your work as midi files.
Having said that, with such a program and others, brings you into contact with possible latency issues, and the joys of trying to reduce these and other software issues - but that's another story...........
If you never try, you'll never know what you've missed.
Let us know how you get on.