To get you the best advice, would you give us some more information about your system:
What version of Windows are you using including Service Packs and whether 32 bit or 64 bit as well as the Name and Version ID of the Norton product that you are using -- Help / About is where that is, in the format of nn.nn.nn.nnn
If you have the COMCAST version of Norton 360 / Security Suite and not the normal commercial version please be sure to tell us.
If you get any error messages please give the exact wording of them as well as any other background that could be helpful.
Tell us a little about your computer too including amount of RAM and of free space on the hard drive ....
The thing I want to know is, is this happening because my computer has updated itself and someone has stuck this thing in recently (the warning)? .....because I never used to see such a warning on my computer. Today, I was simply watching a short news video (I use Google Chrome browser) and got the warning--it said Google Chrome was the culprit....I often get a warning while using Painter or Photoshop but that is not too surprising.
And, like the original questioner...what should I do about it? Is it necessary to do anything? Or is it just there to give me something more to worry about?
I have Windows XP, Home version, Pentium 4 CPU 3.00GHz, 2.99 GHz 1.5 GB ram,
If you aren't noticing any slowdowns, ignore it or turn it off. "High" memory or CPU usage isn't in itself bad. On the contrary. If you are, say, playing a game, you want it to use all available resources, or performance will take a hit.