Spyware Doctor has been around for years, protecting PCs against adware, Trojans, keyloggers and more, but in the ultra-competitive world of Internet security that's no longer quite enough. And so PC Tools have added a powerful antivirus engine, too, ensuring the program can handle the full range of threats you'll find online.

It needn't take long to inspect your system, either. The default scanning options check running processes, applications, startup files, and commonly infected areas like the Registry, Hosts file and Layered Service Providers, which means even the largest hard drives will be analysed quicker than you'd expect.

Of course you can also run a full system scan for increased security, and the fast engine means even that won't hold you up for long. Or if you just need an immediate check, a customised scan can be over in seconds. An integrated scheduler means whatever option you choose can also be set up to run automatically, even when you're not around.

The Spyware Doctor benefits don't stop there, though. You also get a feature they call Immunization, which prevents your PC running any of the malicious ActiveX objects in their database. File Guard dynamically monitors your system, looking for malware files, unsafe Outlook e-mail attachments and so on, then prevents you from accessing them. And a heuristics-based module looks to detect and warn you about the presence of rootkits.

Perhaps the best news of all, though, is this isn't a trial edition. It's not going to stop after three months, or six, or even a year, and demand cash before it'll get back to work. In fact this program isn't time limited at all, so you'll be able to use it, and receive regular updates, for however long you need.

Upgrade to the regular version of Spyware Doctor with AntiVirus and you'll benefit from many more real-time protection features. These will prevent malware from configuring itself to automatically launch when your PC boots, for instance. They'll detect and block hidden processes from running, prevent changes to your network settings, wipe malicious cookies, stop malware hijacking your browser search and home pages, and more. This would normally cost around £20, but you can upgrade for about £16 at www.pctools.com/spyware-doctor-antivirus/free/promo/VNUSD0907. And the same page also offers 20% on other PC Tools software, which includes a Registry cleaner, privacy tool, spam blocker and more, so it's well worth visiting www.pctools.com to discover exactly what they've got on offer.