Open cubase and along the top of the screen you'll see options.
Go to Options/Audio setup/System
When you see the Audio system setup screen, select 'Global disable' in the monitoring box.
You should hear what you play in real time. The part you record may not play back in sync
and you may have to drag it with the mouse to get things to sound in time. It does depend
on the spec of the machine and the way it has been set up for audio.
If the delay is still a major problem, then you may need to invest in:
1. A good soundcard.
2. A separate and faster hard-drive for audio only.
I still believe (although some experienced PC users here disagree

) that the best system for
audio work is A PowerMAC G4.
Each to his own really.