I've got an AT&T 'mifi' and a Windows Vista Home Premium SP2 laptop.
The laptop will connect to the mifi wirelessly and get the correct ip address, default gateway, etc. However, I cannot ping the gateway or anything else from the laptop.
If I connect the same laptop to the same mifi with a cable, everything works fine.
If I connect the same laptop to a different WAP wirelessly, everything works fine.
If I connect a different laptop to the same mifi wirelessly, everything works fine.
Firewall is off.
I've uninstalled and reinstalled all network device drivers several times.
Turned off IPv6.
Flushed DNS.
Ran netsh winsock reset and netsh int ip reset c:\reset.log.
Of course ran MalwareBytes, AVG, CCleaner, tweaking.com Windows Repair Tool. Did fix a few permissions problems and corrupt system files but didn't find any malware/virus.
Also ran...