Intel does not have a driver or software for your adapter in Windows 7, which is why the prowin32.exe package you downloaded cannot find your adapter. The driver that came with Windows 7 is the only driver for that adapter in Windows 7.
Is my Intel® Ethernet Adapter supported in Microsoft Windows 7*? has the information.
You reported that the Intel® Device Update Utility had you download an old Windows 2000 software package. Can you tell me the vendor, device id, subvendor, and subdevice id information from Windows device manager for your adapter? I can use that information to troubleshoot what went wrong and get it fixed. Thanks.
Windows 7 Device manager Intel(R) PRO/1000 MT Desktop Adapter Properties reports the following under Details: