What model Tivo are you using? also, is it a new box, subscribed to Tivo Service?
With the little information you provided, its hard to determine a proper solution.
Series 2 (PLS, sold)
TiVo HD 1TB (157 HD Hrs, PLS, "652")
Juliet Basic (PLS)
OTA! OTA! OTA!
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!