Can you help me?

I bought a small Sony Condenser Microphone which fits into the mic jack of my laptop.

I assumed (naively?) that this would then work automatically - and supercede/override the built-in laptop mic.

It doesn't seem to work: for example -

if I plug it in and (say) use the Windows Sounds Recorder ("testing testing 1-2-3") - nothing is recorded! (If I take it out and use the built-in mic, it works fine).

Are there other settings I have to change? If so, how?

Am I missing something basic here (very possible!)