quote from "http://dslnuts.com/tips_tricks.shtml"
"HOW TO SET THE PROPER NIC DUPLEX SETTINGS:
Win98/ME: to change to half-duplex:
* Open Control Panel.
* Double-click Network.
* From the scrollable list, select your Ethernet adapter (rather than any dial-up) with a green icon.
* Click the button Properties.
* Click the tab Advanced to bring it to the front:
* In the Property box, the property name to be selected varies according to model of ethernet card. Examples are: Network Link Selection, Media Type, Connection Type, Duplex Mode, or any similarly-named property which can have Values looking like Auto-Negotiation, or 10BT, or 10BaseT.
* In the Value box, select a value which either (a) explicitly says half-duplex or semi-duplex, or ( at least does not say full-duplex [e.g. 10BaseT on its own is OK]. If there is a choice between 10 and 100 with half-duplex, choose the 10. Do not choose 10Base5, 10Base2, or AUI.
* Click OK to exit the Adapter settings.
* Click OK all the way out - you might need to restart.
Windows 2000 or XP: to change to half-duplex:
* Open Control Panel.
* Double-click Network and Dial-up Connections.
* Identify the icon for your cable modem connection: usually Local Area Connection.
* Right-click that icon and select Properties.
* Under the ethernet adapter icon, click the button Configure.
* Click the tab Advanced to bring it to the front:
* In the Property box, the property name to be selected varies according to model of ethernet card. Examples are: Network Link Selection, Media Type, Connection Type, Duplex Mode, or any similarly-named property which can have Values looking like Auto-Negotiation, or 10BT, or 10BaseT.
* In the Value box, select a value which either (a) explicitly says half-duplex or semi-duplex, or ( at least does not say full-duplex [e.g. 10BaseT on its own is OK]. If there is a choice between 10 and 100 with half-duplex, choose the 10. Do not choose 10Base5, 10Base2, or AUI.
* Click OK to exit the Adapter settings.
* Click OK to exit the Connection properties. "
VanBuren