You can't assume that just because you connected at a speed like 48.3KBps that you will stay there. Today's modems automatically fall back to a lower speed if the line noise is too high to maintain a faster connection, but sometimes they fall back too soon or too far. Here's how to do it: Click Start the button. Select Settings. Click Control Panel. Double-click on the Modems icon. Select your modem. Click the Properties button. Click the Connections tab. Click the Advanced button. In the "Extra settings" field, type S36=7 Click OK to save your settings. Source: - How to improve your dialup modem preformance?