Use the ones built into Windows if you're on Windows 8.1 or newer.
Windows 7 needed drivers.
Windows 8 needed drivers, but NOT the Windows 7 ones (but that was back when Windows 8 was new, I imagine there is some kind of "group package" now).
If you're using Windows 7, and you really, really can't find them from a decent source, I probably have them kicking around. But Intel probably doesn't list older cards, but probably still has the downloads up if you dig (that's their typical way).
I found a Vista download page that seems to apply to all Intel Gigabit NICs.... but.... it says:
"Microsoft Windows Vista does not support the following devices:
IntelŪ PRO/10GbE CX4 Server Adapter
IntelŪ PRO/10GbE LR Server Adapter
IntelŪ PRO/10GbE SR Server Adapter
IntelŪ PRO/100+ Dual Port Server Adapter
IntelŪ PRO/1000 T Server Adapter
IntelŪ PRO/1000 F Server Adapter
IntelŪ PRO/1000 Gigabit Server Adapter
IntelŪ PRO/1000 PF Quad Port Server Adapter
IntelŪ PRO/1000 PT Quad Port Server Adapter
IntelŪ PRO/1000 PT Quad Port Low Profile Server Adapter
IntelŪ PRO/1000 XT Network Connection
IntelŪ PRO/1000 XT Server Adapter
IntelŪ PRO/1000 XF Server Adapter
IntelŪ PRO/1000 XF Network Connection
IntelŪ PRO/1000 T Desktop Adapter IntelŪ PRO/1000 T Network Connection
IntelŪ PRO/1000 XT Desktop Adapter
IntelŪ PRO/1000 CT Network Connection
IntelŪ Gigabit VT Quad Port Server Adapter
IntelŪ Gigabit PT Quad Port Server Express Module
The software drivers provided on this page are generic versions and can be used for general purposes. "
I'm wondering if I happened to pick the wrong Intel PRO/1000 model ?