Compaq Presario SR2163WM and Siemens SpeedStream 4100 DSL Modem using Windows Vista Problem and solution. My neighbor just bought a Compaq Presario SR2163WM With pre-installed Wndows Vista Basic home edition and subscribed to ATT DSL service with a Siemens SpeedStream 4100 modem. With this combination the pc and the modem could not communicate with each other, i.e., the pc continuously is searching for the network for a very long time and may never find it. To fix this, do the following: Open the Control Panel Select Network & Sharing Center Select Manage Network Connections Right Click on Local Area Connection Select Properties Under Connect Using: press Configure Now, Select Advance Under Link Speed / Duplex Mode, select: 10Mbps / Full Duplex Under Optimal Performance, select Enable Now, go back to the Control Panel and select Network & Sharing Center Check if Network shows as (Public Network), if so, then, Select Customize Select Private Network and save the changes You’re done! It appears like it doesn't like the auto speed feature of the internal motherboard ethernet card and is unable to lock into this under Windows Vista. Setting it to Auto or changing it to 100mbs did not work for me.