How to convert the audio sample rate?

[misfits967]

I record using a Fostex MR8 digital recorder and then I put all the tracks on the computer to mix them together. The problem is, the Fostex records these tracks at a 22 kHz audio sample rate. When I open up the program KRISTAL and import the tracks, it plays that track twice as fast because the program's rate is 44 kHz. Is there a way I can convert the 22 kHz sample rate to 44 kHz. Is there a free program? And will this affect the sound in any way?

Thanks