If your modem it timing out during file transfers or loading Web Pages,you might try increasing the timeout period.
To change it
01. Start Regedit
02. Go to HKEY_LOCAL_MACHINE / System / CurrentControlSet / Services / Class / Modem / XXXX / SettingsWhere XXXX is the number of your modem
03. Move to the right panel and double click on Inactivity Timeout
04. The number of minutes for a timeout should be entered between the brackets.
05. For example, a US Robotics Sportster could have S19=<30> to set it to 30 minutes.