A study of all of Microsoft's security bulletins in 2009 showed a common thread that you should keep in mind when setting up computers for your friends, relatives or coworkers: 90 per cent of the most serious vulnerabilities were nullified by removing Administrator privileges.
That 90 per cent figure, from a BeyondTrust security study (direct PDF link, ahoy) applies to "remote code execution" vulnerabilities, which are basically the worst kind of viruses, worms and trojans around. Across all security flaws that Microsoft reported, 57 per cent were not a problem for standard Windows 7 users lacking Administrator access, with similar percentages in other Windows versions. The even better news: exploits that tried to hook in through Microsoft Office and Internet Explorer were basically nixed out too.
IT pros likely know the benefits of reduced system access across wide swaths of workers, but for those setting up a shared family computer, or helping out a very virus-prone friend or relative, it's worth keeping in mind.
90 percent of Windows 7 flaws fixed by removing admin rights [Ars Technica]