The Risk of Running Windows XP After Support Ends April 2014 - Microsoft Security Blog - Site Home - TechNet Blogs

There is a sense of urgency because after April 8, Windows XP Service
Pack 3 (SP3) customers will no longer receive new security updates,
non-security hotfixes, free or paid assisted support options or online
technical content updates.  This means that any new vulnerabilities
discovered in Windows XP after its “end of life” will not be addressed
by new security updates from Microsoft.



More info @ :- The Risk of Running Windows XP After Support Ends April 2014 - Microsoft Security Blog - Site Home - TechNet Blogs