well first of all IVE got to say IM a begginer on computers xD

my problem is that om my desktop PC (windows XP SP2) i have a wireless ADAPTER(Nexxt Solutions: Wireless G 54M USB adapter)[link to adapter pic http://www.newtekuy.com/catalog/images/nexxt_nw230nxt16.jpg]which normally after loggon connects to my linksys (ROUTER) but YESTERDAY i let my cousin use the computer and the next day the wireless adapter didnt turn on on the computer and the sign didnt appear.
i thought it was disabled so i went to network mconnections and my connection wasnt there (the adapters light used to be on,now its not) and tryed to add a new wireless connection but the computer doesnt find the adapter (which is connected) this adapter installs itself when connected so it didnt have an installation CD when i bought it(from store).
its not the adapter since i just used it on my laptop and its not the USB port since i connected my camera to it

Have you tried restarting the computer with the wireless device already in the computer?
Can you also try another USB port?

Any recent changes in the computer? (downloads/installs/hardware changes/ect....)