So near and yet so far

I have some audio cassettes with focus group recordings on them: central to my MA research. However, they are largely inaudible (hiss, voices too quiet) because I took no care in selecting and positioning the Walkmans when conducting the focus groups.

Is this 'Groove Mechanic' likely to help me? If so, what does downloading it involve? I've never really used computers before and so might be just a touch out of my depth.

I fear the worst - who will tell me it ain't so?