Microsoft end of support for Windows XP and Office 2003 - April 2014

As per Microsoft Support Lifecycle Policy both Windows XP SP3 and Office 2003 will reach end of support on April 8, 2014. The end of support means that after this date there will be no new security updates, non-security hotfixes or patches for both those products available. Technical support for XP from Microsoft will also not be available any more. Running XP SP3 (or lower) and Office 2003 after the end of support date may expose the company to potential security and compliance risks. Worth consideration is also fact that aside of vulnerable system it is expected for several third party software vendors to stop support of their applications on XP Platform after April 2014 as well - this ads additional danger of vulnerable applications and multiplies the possible infection vectors.

For Symantec Endpoint Protection customers running SEP 11.x and 12.1 on XP platform - Symantec will continue releasing definitions for all so far supported Windows platforms - including XP SP3 after April 2014. Please note though that in certain cases Symantec Support may not be able to provide full-scope resolution on XP systems due to lack of available security patches for it. Additionaly SEP 11.x reached its End of Limited Support on January 5, 2014 and upgrade to 12.1 release is highly recommended. For more information please refer to below Symantec documentation:
 

FAQ: Upgrading Symantec Endpoint Protection 11.x to version 12.1.x

Microsoft End of Support on for Windows XP and what it means for SEP

References:
http://www.microsoft.com/en-us/windows/enterprise/endofsupport.aspx
http://windows.microsoft.com/en-us/windows/lifecycle
http://windows.microsoft.com/en-us/windows/end-support-help