Problems with atheros L1 ethernet adapter in Win7 x64

Hi, i have windows 7 x86 build 7022, with an onboard ethernet adapter "atheros L1" with vista drivers, RUN OK. I installed Win7 x64 uild 7057 with the same drivers, but the problem is that after a few minutes the network adapter looks "unplugged" if i restart win7 the problem disappear... but did not have that problem before with win7 X86 build 7022.
And is very tiring, restart the computer each time this happens.

Sorry for my bad english.

That's a very strange problem, if you try to repair the connection in the "network and sharing centre" does it spring back to life?

Also, have you tried searching for drivers for it on Windows Update?

yes i tty to repair the connection but nothing

in Windows Update there are no updates or drivers for mi network adapter...

in windows x86 build 7022 works fine! :/

thanks!