How can I retrieve a cassette tape quality?

Question

The sound is very faint and noisy.

Answer 1

Try a cassette head-cleaning tape, or you can put some cleaning alcohol on a q-tip and carefully clean the heads yourself. If it's not the heads, you could be struggling and may have to give it up as a bad job...
To make sure, try the same tape in a different player..
Laterally thinking, you could try transferring to your PC hard-drive then use software to clean it up - but obviously the worse the tape sounds, the less likely it is that you will get good results.
visit:
http://www.cassette2cd.co.uk/diy
for more information, and:
http://www.cassette2cd.co.uk/downloads.php
for free software etc..

Answer 2

You can't. The loss of quality is irreversible.