Follow this steps and try
in windows 7
On the start
screen, scroll to Tasks
, click settings
, click TV
, and then click Set Up TV Signal
Follow the steps to connect a TV signal, depending on the type of tuner or tuners that the cable is connected to
The Windows Media Center TV Pack has an "Auto Select" option which
removes channels that have a weak signal from the EPG. To run the "Auto
Select" option to check the list of available channels and to evaluate
the signal strength for each channel, follow these steps:
- Start Windows Media Center.
- In the Start window, scroll to Tasks, click Settings, and then click TV.
- Click Guide.
- Click Edit Channels.
- Click Auto Select.
"Auto Select" option tests each channel. Based on whether a strong or a
weak signal is found, the "Auto Select" option puts a check mark in the
box next to the channel. As soon as the detection process is complete,
you have to click the "Save" option to save the newly selected channels
to the EPG.
esle if the problem still persists
have a look aon the microsofts support in the following linkhttp://support.microsoft.com/kb/955485/en-us