Digital TV likes clear signal path

Q If I buy a new digital TV, can I just plug it in and use it, as I do the old TV now? My son insists that it has to be hooked to an antenna, but the old televisions worked fine without one.

KATHY EHLEN, MINNEAPOLIS

A Whether you'll need an antenna depends largely on the terrain and other buildings in your area. Digital TV signals can be a bit more difficult to receive than analog signals because they are more sensitive to barriers such as hills, trees and buildings.

To learn more about HDTV antennas (and avoid getting scammed by claims that you need a "special" antenna), see www.hdtvantennalabs.com/hdtv-antenna-guide.php, which offers tips such as: "There is no such thing as an HDTV antenna. Your antenna has no idea whether your signal is high definition or not."

Q I cut out an article you wrote some time ago regarding free anti-spyware and firewall software but when I tried to download using the websites you listed, I was told the file couldn't be found. Are they still available and, if so, how do I access them? I'm a novice, but want to download this since the free McAfee software on my new Dell computer has expired.

MARY HATCH, MINNEAPOLIS

A For the free Spybot anti-spyware program, go to www.download.com, find Spybot Search & Destroy in the list of most popular downloads, and click on the link, which takes you to the Spybot download page.

Q I recently updated the latest version of Norton Antivirus on my Windows XP PC, but since then, my computer has been freezing. I often have to reboot several times to get it to work properly. Why is this happening?

CHARLIE PAULSEN, MOUND

A I suspect your Windows XP computer lacks enough memory to handle Norton AntiVirus 2009. Symantec, makers of the software, says the PC "must meet minimum Windows Vista operating system requirements."

That means a minimum of a 1 gigahertz processor and 512 megabytes of RAM memory -- and for optimal performance you need 1 gigabyte of RAM (the amount required for the widely used Windows Vista Home Premium).