No input device found

I am running Windows Vista on a Dell PC. Audacity 2.0.0 does not find any input devices - it cannot see my sound card. How do I get it to recognise this, please?

Go into the Windows Control Panel Sound settings and ensure that the recording device that you want to use is recognised and enabled.
See here for more information:

Thank you, but of course I checked that and all is well with it according to Device Manager.

I had no trouble with Audacity (earlier version) on my previous computer, which ran XP, but both my daughter (Win 7) and I (Vista) now have this problem, both with the earlier version and with the upgrade to 2.0.0.

Any other suggestions anyone, please?