Mobile USB Soundcard

I have 2 USB soundcards that worked from the time I registered earlier this year. But now they do not work. When I plug them into the USB port it is now not recognized, and the blue light does not come on.
Do I need to change settings somewhere in my laptop setup, or do I need to purchase another sound card?
Since my soundcard does not work I am not able to use products at all. Either it be 'U-Mix or Home 7'.
Do I need to change settings somewhere in my laptop setup, or do I need to purchase another sound card?
Since my soundcard does not work I am not able to use products at all. Either it be 'U-Mix or Home 7'.