Microsoft has published a security advisory, warning users of Windows XP that they must update their installations of Flash.
Windows XP came with version 6 of the Adobe Flash Player, and it has been discovered that that version contains a number of vulnerabilities that could be exploited if you visited a boobytrapped webpage.
The end result? Malicious code could run on your computer, opening a backdoor for hackers to gain access, potentially stealing your identity or turning your computer into part of a spam-spewing bonnet.
And you wouldn't want that would you?
So, double-check that your version of Adobe Flash is current. Visit this page on Adobe's website to run the test (it only takes a few seconds), and you'll quickly know if you're up-to-date or not.
If not, update Adobe Flash immediately from http://get.adobe.com/flashplayer/