Full user review
Works in the background but can be disabled if required. Thorough. It doesn't take much to set it up as YOU require - mainly it's a case of 'hiding' the updates you don't want.
Unless disabled starts up with windows - this can be annoying with a slow start-up. We need one for Linux! Oh. And it sometimes misses that you already HAVE the latest update - but this may be my fault in not adjusting a setting.
This resource works well with Win 7 and Vista and, as far as I know, previous versions of Windows (XP for sure). I use it on four computers - two desktops and two laptops - and it differentiates between the machines as well as the OSs. In other words, there are four TechTrackers specifically set up for me in my account (FREE!). Given that I use automatic updates from MS and occasionally run ASC Pro through the systems, it was a pleasant surprise to discover that they don't clash. Another good service/resource from CNET