(from http://forums.techguy.org/networking/459097-remove-old-network-adapters-os.html)
go to this Key in the registry -
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network\
in there you'll see a bunch of numbered items one of them has a Class of NET under this key is a more of the odd numbered items each will have a connection key under it. Notice where it has the Name field. you can delete the old ones that no longer exist and then change the name of the one that does exist to Local Area Connection.
I.E
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Network\{4D36E972-E325-11CE-BFC1-08002BE10318}\{C92105C4-51E7-4D12-B3FE-1B343B6F4DD7}\Connection]
"PnpInstanceID"="PCI\\VEN_14E4&DEV_1696&SUBSYS_12BF103C&REV_03\\4&3A321F38& 0&10F0"
"MediaSubType"=dword:00000001
"Name"="Local Area Connection"
"ShowIcon"=dword:00000001
"IpCheckingEnabled"=dword:00000001
No delete the subfolder under that but above connection (the one that is the old one)
in the example I gave it would be -
{C92105C4-51E7-4D12-B3FE-1B343B6F4DD7}
Another thing you can do is rename the one that says Local Area Connection #x by changing the "Name"="Local Area Connection" field of the one I.E. if windows displays Local Area Connection #5 find the "Name"="Local Area Connection #5" and change it to "Name"="Local Area Connection"