Hi. I have a semi acoustic guitar. When i connect the cable from my guitar to my line-in in my pc, there is no sound in my speaker? Can anyone tell me why is this so?
And when i connected my electric guitar with my pc, atleast im getting a clean sound in my speaker!!
Does anyone know what is the problem with my semi acoustic guitar?? or its normal??
I also brought yesterday a external sound card creative sound blaster audigy. And im not getting any input of my guitar to guitar rig software also?? Im not able to hear anything of my guitar in that software!!
Does anyone know about all this stuff?

And if i buy a amplifier and put the guitar input to that and an output from amplifier to my cabinet..will i be able to run guitar rig from my pc and get the output?

I presume that everything is right with your guitar cable, connectors etc.

If your semi acoustic guitar has a piezo pick up, it will not work on line input. Level of the signal from piezo pick up is very low. It might work on your mic input, give it a try. The best solution is to obtain a piezo pre amp.
Have a look here:

http://www.playbetterbluegrass.com/barcus_berry_preamp_5361_prd1.htm
http://www.alexrice.co.uk/content/projects/piezo_preamp.php

My best,
Aleksandar