Follow these steps to change your dial-up number in Windows 9x/ME or 2000.
1. Left-Double Click on the My Computer icon on your desktop.
2. Left-Double Click on the Dial-Up Networking Icon.
3. Right Click on the Dial-up Icon and Left-Click Properties.
4. Left-Click on the ‘Telephone number:’ dialog box and type in the new number appropriate for your area.
5. Click OK to save your changes.