The usual "narrow it down" syndrome comes into play here. Try the headset on another PC to check (chances of failure are about nil, but at least you will know for sure) if they work there.
An old trick of mine, if there is nothing obvious in the device manager, etc. is to download a freebie alternative and there are many. Realplayer, Musicmatch.or your soundcard diagnostics, plus countless others If it works there, then your primary playback porg is having a wobblie. If not, it points more towards connections and sound cards. Then try another headset with primary proggie. With only a short lifetime, you can narrow things down really well and then let us know the progress report. There be Dragons here, so if you have done the above or similar, then you (we?) are much better placed to work on.
This may be revealingly sad, but by following a logical sequence, you know where you are and it can even be fun trying to find where it has all buggered up.
Oddly, there is a thread on JB at the moment, (Capt Cane?) Where no sound emerges from my machine or Hi Fi, so a voyage of discovery may be in order tomorrow night.
Conan