I think I am being quoted out of context...It would be more accurate to discuss the IR Receiver/Blaster for use with a Digital STB... "he has a verizon fios set top box"
What remote are you using? Are you controlling an STB? I am talking about the Microsoft XP MCE Remotes...and not ones that require special software or setup to work with Windows 7 Media Center.
When XP MCE came out, most households in the USA did not use or require the use of STB's. Now it is the standard. In order for MCE to change the channel on a setup that uses an STB in Vista or Windows 7, a Vista/Windows 7 IR Receiver and Remote are required. Even the IR standard has changed on these devices from XP MCE to now. Microsoft has stopped making them and now licenses the manufacturing of the Green Button required remotes.
What exactly is the make and model of the remote you are using, what IR standard is it using and what dongle/ IR Receiver are you using? Did you have to customize anything? Does your Remote have 'RC6 IR' on the back?
Here are hundreds of people who had difficulty with old remotes/receivers and VMC....I suspect we are just now getting folks having similar issues when they upgrade from XP to Windows 7. http://www.usbuirt.com/phpBB2/viewforum.php?f=2
The simple answer is (for a simple solution) that at least a Vista Certified IR Receiver and remote are required to control a Digital STB and your TV tuner must support it.
If you do not use an STB, you may also not need a remote, but again, there appears to be many users who cannot get to the point of understanding much of what is happening in the setup, which is based on auto-configuration files that MS uses to configure your devices. If you do not have an STB, you do not need the IR Receiver/Blaster to control it. You also do not 'need' a remote, but if the software and drivers that are installed are looking for one, the auto setup in MC will want to configure it.
These questions are best asked to the manufacturer of the TV Tuner and also to your cable/satellite provider for specific recommendations.
I hope this helps.