I upgraded (?) my son's pc from windows 98se to win xp home edition. All was working fine before installing xp. Now the we can't dial out. Keep getting error 797. I have removed and reinstalled the modem and updated drivers several times. Pulled a modem out of my pc running xp and it still would not work on his pc. Have been on the phone with microsoft tech support for hours without any remedy. The modem is listed in device manager and is reported to be working ok. After trying to log on (dial up connection) and getting error message 797 i go to dial up properties and there is a "red" X next to dial using this modem and a message says modem removed. can anyone help? Thank you.