I record a tape into the computer.
The problem is that this tape played so many times so the sound Demolished.
I used ‘Noise Removal’ to remove the noise that was where it was silent, but it didn’t help much.
what can I do to Improve the sound?
Probably you don’t if you are taking about creased or loose tape.
Attach an audio sample so we can hear it if it’s something other than creased tape.
If it’s creased or loose tape sometimes manual rewinding with a pencil can help a little.
Gale
It’s probably worth cleaning the heads and the transport mechanism - see this Audacity Wiki page: http://wiki.audacityteam.org/wiki/Recording_from_Cassette
WC