cannot hear recording whilst recording

I am a non technical user. Using Windows Vista Home Premium SP2, Audacity 2.0.5 downloaded using the installer.

Followed the manual but could not hear the recording whilst recording. Tried again today and whithout changing anything I could hear it! Stopped recording and when restarted, could not hear it again! Any ideas?

What are you recording? A USB cassette player? Make and model number?

I am trying to record an LP using using a zenox turntable connected via USB

In which case have a look at this tutorial in the Audacity Manual:

and/or this FAQ: