just installed norton. any good?

Don't use the registry cleaner portion.

The most recent versions of Norton have a pretty good reputation for anti-virus protection.

You should avoid all registry cleaners if you can stand it. If you just can't help yourself and HAVE to do something about your registry, use CCleaner, but say "yes" when it asks you if you want to back up the registry before it cleans.

You can improve your startup times manually and should probably know how to do that anyway.

"Comcast says its a $160 value."

Isn't that what they all say!

From reading posts at community.norton.com, I get the idea Comcast's version and Norton's are always slightly out-of-sync. You'll get your anti-malware updates, but engine upgrades would rest on Comcast catching up. Protection is still there, mind you. But any bug fixes may take a little longer.

As the others have mentioned before, do not use any kind of registry cleaner unless you know exactly what you are doing and are completely familiar with your computer's intestines
Norton used to have a reputation for blue-screening and software which was very heavy on the computer until the 2009 products, which were rebuilt from scratch and made to run silently and light-footedly in the background. Unfortunately, its reputation for being a "resource hog" is still lingering around - although this is actually no longer the case at all. Reading around, every antivirus software -regardless of vendor - seems to have had this reputation at one time or the other.
Example: Norton product versions till and including 2008 had a separate LiveUpdate module. During LiveUpdates, it was common for the computer to slow down or freeze, and if you removed the program, the module had to be uninstalled separately. This is no longer the case, and everything is bundled together very neatly; and as of today, Norton has its own task scheduler (meaning that tasks will no longer get stuck in Windows Task Scheduler). I could write a lot more...but...
...in the end, you will find that choosing your antivirus program is a rather complex business. You will discover people arguing for and against this and that antivirus software ad infinitum et ad nauseam.
For this reason, most antivirus software vendors provide trial versions (but you have to deinstall them thoroughly with the vendor's removal tool if you're dissatisfied and do not want to keep the trial version).
Back to the Comcast version of Norton: you can find a comparison chart between the normal Norton Premier edition and the Comcast edition over here:
Constant Guard - products - constant guard protection suite

By the way, the only difference between the normal Norton Premier and Standard versions is the size of the online backup storage.

irbullet
Re Norton.

1. Is it good?
2. I want my Pc safe

1.The first answer depends on whose opinion you seek at any given time.
As with any AntiVirus program there will be supporters & detractors.

2. From a BSOD perspective Norton is often implicated.
Thus I would be hesitant to recommend it.

To keep you PC safe from the evils of the internet your basic protection should include

*Anti Virus Program [ MSE is popular & is used by many people here]
*Anti Malware Program
*Firewall
*Router / firewall
& most importantly
*A hand on your mouse that can control what it clicks on.

It is important to update programs & scan regularly.