Ich habs auch schonmal gemacht (unbeding den Registrypfad vorher sichern!!):
hier zwar in englisch, aber immerhin.
Der Link und die Stelle:
http://forums.whirlpool.net.au/archive/820518
I just wanted to mention here, for anyone else having this problem (it's the number 3 hit on Google for "rename network adapter"), that I figured out how to fix this once and for all. It's not exactly as posted in that link, but it's close by.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network\{}\Descriptions
(where {} is whichever key has Descriptions under it; there are 4 bracketed keys under Network on my setup, and only the top one has Descriptions)
Under that key you should see a bunch of Multi-String Values with the names of all your installed adapters and miniports. Each has a number beside it indicating the instances of that device. Delete the Multi-String Value of the adapter you want to reset the numbering on, uninstall the adapter in Device Manager, then reinstall. You should be back to no numbers again.
Cheers!
Chris