If you want to save your ISP settings (name, phone, login id etc.) for future installations:

Start Regedit
Go to HKEY_CURRENT_USER \ RemoteAccess
Select Registry / Export Registry
Make sure Selected branch is checked
For the name, enter any name that will help you remember the purpose of the .reg file
Now if you need to restore your ISP settings after a new installation of Windows, you just need to import this file