Tweaking DSL Speed (MTU Size) Setting in Windows XP

The default Maximum Transmission Unit (MTU) size for PPPoE (DSL) connections in Windows XP is typically set to 1,480 or 1,490 bytes. However if find you can’t browse some Web sites or send e-mail messages with attachments, your DSL connection may work better with a slightly lower MTU size setting (somewhere between 1,400 to 1,490). You can refer to another tip on this site for information on how to test out what MTU size is best for your Internet connection. To edit the MTU size in Windows XP, you must first add the following keys to the Windows Registry: Hive: HKEY_LOCAL_MACHINE Key: System\CurrentControlSet\Services\Ndiswan\Parameters\Protocols\ Hive: HKEY_LOCAL_MACHINE Key: System\CurrentControlSet\Services\Ndiswan\Parameters\Protocols\0 Then add the following entries to the 0 key: Name: ProtocolType Type: REG_DWORD Value: 0x00000800 Name: PPPProtocolType Type: REG_DWORD Value: 0x00000021 Name: ProtocolMTU Type: REG_DWORD Value: desired MTU size