Microphone Not Working...

Okay, I have an Acer Aspire (ASE380-UD480A). I'm running Vista Home Premium on it.

I just installed a new sound card (Creative Sound Blaster Audigy SE), as before I was just using the on-board. There are four jacks on the card, three are supposed to be for speakers, one for either speakers or headphones, and one for the microphone (or so the manual tells me).

My first problem is this: Only the dual jack (headphone/speaker, aka: jack 1) is working. I can use either the headphones, or the speakers in this jack. None of the others are working, including the microphone jack, which leads to the second problem; the headset mic ran fine on XP when we had it, but I can't get it to function now. Also (this happened to my brother as well, as he has the same sound card) the front jacks on the computer no longer work (as long as the card is installed). I'd be okay with that, if the damn jacks in the back would just work.

Please help; I'm really not that great with the hardware stuff, etc. so any help at all would be fantastic and very much appreciated.