Maybe you need to increase microphone volume, or recording volume (Control Panel-Sound and Audio Devices). Or your mic is not compatible, e.g. impedance not suitable...
I have a PC with Windows XP. I'm wanting to use a mic so I can add voice audio to movies. I just downloaded Vegas Movie Studio. Problem is, though I get some voice, the signal is very weak. In fact I have to put my mouth right against the microphone to get audible sound (which is then distoreted). I've tried it in Windows Moviemaker and get the same problem. I've also tried using two different microphones, and have made double sure the jack was inserted all the way in. I have ensured that, in "recording controls," microphone is activated.
I would welcome ideas for next steps. I'm not terribly computer literate, but with the help of my ten-year-old son, I've been learning a lot lately--like how to install a DVD burner and a hard drive.