64-bit device drivers have been a Windows Logo Program requirement since it was revised for Vista.
I've been using this Encore adapter since Windows 7 was in Beta or RC:
It was around $17+shipping when I got it. It doesn't appear to be available for less than $40 now.
I use the chipset manufacturer's drivers (Ralink RT2870) - driver-only install, and have never had a problem on Windows 7 x64.
This AZIO adapter also uses a Ralink chipset and is currently $20.
@Beatbuster - The wg111v1 uses an Intersil PrismGT chipset. I could not find a Windows x64 driver for this chipset. The one on Netgear's site is 32-bit. The other versions of the wg111 use Realtek chipsets, (RTL8187L for v2, RTL8187B for v3) so their drivers won't work with your v1.