Why does my network adapter have to be reset so often?

Do an "ipconfig/all" and post the results.

An external USB wifi adapter would also give a clue as to whether ther is something physically or even driver is wrong with the internal card. Have you tried reseating the aircard and ensuring the antenna wires are securley attached? Though, if the computer works well with a router, than physical is not likely the problem.

Have you gone to device manager and removed the network driver? It will rebuild at restart.