I signed up for a Panda account, but I'm not quite sure if that's required or not - the program seemed to work fine before I signed up. only some notes/links on the control panel encouraging me to upgrade to Panda Antivirus Pro (which adds a firewall and Wi-Fi protection). Also, I haven't noticed any pop-up ads or anything of that sort. Power users will no doubt want more control, but Joe Average users with slight geekish tendencies will likely be happy enough.

The Windows 8-ish control panel GUI is more designed for fat-fingered users of touch screens than for handsome, erudite users of 'classic' desktop PCs, but it's straightforward if not very elegant. Major features - Real-time protection, Process Monitor, and USB Vaccine - can be turned on and off individually, as can many smaller sub-features. I'm guessing that 'updates' include both virus definitions and program updates. The Update feature is automatic, and I don't believe that it can be turned off(?) there's also an on-demand 'Update now' button. Big items include customizable scans, a scheduler for scans, and exclusion lists. Panda is easy to install and setup and allows the user a reasonable amount of control over the settings. How well Panda is protecting my system, I haven't a clue, but it tests well in the various antivirus tests I've seen on the Web. In any event, I'm glad that I switched, as Panda has so little impact on my system's performance that it's almost like having no antivirus program installed at all: my computer starts quickly (with no warnings or errors on my Event log), programs launch/open quickly, and files open/load quickly.

(Avira still lists Windows XP in their System Requirements, but the Web page they referred me to does indeed show that Windows XP support ended on : ) I recently switched to Panda Free Antivirus after experiencing a few minor problems with Avira Free Antivirus, which I'd been using for several years I reported the bugs to Avira and they informed me that they've ended official support for Windows XP and will not be addressing the bugs. Athlon XP 3000+ CPU (w/SSE but not SSE2 or above support)

Panda free antivirus offline installer