Hi all,hope you can help me

I'm attempting to capture some home videos on vhs.I'm using a Conexant 2388x capture card for the video and the line in input on the motherboard for the audio (Realtek AC97)
Everything seems ok when I capture but on playback the video is fine but the audio is at such a low level I have to have the volume right up (windows media player) just to hear it and then I get a lot of background noise,hiss etc
All input levels are set as high as possible.
Any suggestions ?
Cheers
Daz