Microsoft Cordless Phone System was a 900 MHz cordless phone introduced in 1998 that was marketed as a phone that combines the power of the PC with the latest telephone technology. It was discontinued for about one year after its release and the software (Microsoft Call Manager) only works on Windows 95/98 and not on Windows NT, 2000, Millennium Edition or XP. No substitute for the Microsoft Cordless phone system is currently planned to be released.