My Norton subscription ran out. I bought an upgraded version of Norton Systemworks from Costco (not downloaded) and then the fun began. Windows refused to boot, etc. I finally got back on and yanked Norton out by its nasty roots. My computer seems to do stuff faster now. Norton, in my opinion, is a bloated, intrusive hunk of software. I got sick of it reminding me to renew every time I logged on, etc. And good luck trying to get anybody to talk to on the phone.
I use the Firefox browser, the Windows firewall and the Spybot free spyware remover. I'm also careful what I open from e-mails and such. I'm embarrassed to say I haven't re-installed an antivirus program since last November. My cable company (Cablevision) offers one free, as well as a free firewall. you have to download the software from its web site. I hope to get around to it soon.