You said you have no problems pinging so there is something going out, meaning the adapter does communicate
As a last resort you can try uninstalling the adapter from the device manager and reboot and let it refind it, maybe a freshset of drivers will help.
Another thing to try is to run a check disk on your hard drive and have it check the system files.
Third thing if neither of them do anything, go to the run command and type in:
sfc /scannow
this will check for corrputed system files - you may need your disk in the machine in case it has to extract files to repair damaged ones.