(MoneyWatch) To many security experts, there's nothing especially new or controversial here, but Microsoft's latest Security Intelligence Report confirms that Windows XP is more vulnerable to malware than any of Redmond's more modern offerings.
There, you'll find that Windows XP is about twice as like to get infected as any of the more modern operating systems, including Windows Vista and Windows 7.
The study shows that overall, infection rates are rising, though Windows XP remains significantly more at risk than Windows Vista or Windows 7. XP's infection rates in particular jumped dramatically in the first half of 2012, due to the worm family Win32/Dorkbot and the trojan downloader Win32/Pluzoks -- and the fact that Microsoft has stopped directly supporting Windows XP with security updates to address such risks.
How can you protect yourself? If you are still using Windows XP, you should seriously consider upgrading to Windows 7 (or Windows 8, which releases in about a week).
If upgrading isn't an option, you should absolutely be sure to keep your antivirus software current.
One other option: Consider changing to a Limited User account. This isn't especially convenient, but by taking away the default administrator status, you'll make it far more difficult for malware to wreak havoc with your PC.