Microsoft to end support for Windows XP but still have about 40% of OS market share

By April 8, 2014 Microsoft will end support for Windows XP and Office 2003 but 38.99% of all computers still run Windows XP.

In 2002 Microsoft introduced its Support Lifecycle policy based on customer feedback to have more transparency and predictability of support for Microsoft products. As per this policy, Microsoft Business and Developer products, including Windows and Office products, receive a minimum of 10 years of support (5 years Mainstream Support and 5 years Extended Support), at the supported service pack level.
Thus, Windows XP SP3 and Office 2003 will go out of support on April 8, 2014. If your organization has not started the migration to a modern desktop, you are late. Based on historical customer deployment data, the average enterprise deployment can take 18 to 32 months from business case through full deployment. To ensure you remain on supported versions of Windows and Office, you should begin your planning and application testing immediately to ensure you deploy before end of support.

Without support your computer will still work but operating systems without support risk Security & Compliance Risks and Lack of Independent Software Vendor (ISV) & Hardware Manufacturers support.

Security & Compliance Risks: Unsupported and unpatched environments are vulnerable to security risks. This may result in an officially recognized control failure by an internal or external audit body, leading to suspension of certifications, and/or public notification of the organization’s inability to maintain its systems and customer information.
Lack of Independent Software Vendor (ISV) & Hardware Manufacturers support: A recent industry report from Gartner Research suggests "many independent software vendors (ISVs) are unlikely to support new versions of applications on Windows XP in 2011; in 2012, it will become common." And it may stifle access to hardware innovation: Gartner Research further notes that in 2012, most PC hardware manufacturers will stop supporting Windows XP on the majority of their new PC models.

The good news however is that in 10 months the number of Windows XP users has gone down from  46.08% of  April 2012 to 38.99% this February 2013. But this is still large considering the number of PCs in the market. The pace is very slow which might be caused by common issues faced in upgrade from Windows XP to Windows 7/8.  Not only are users faced with incompatible and slow hardware they also must upgrade to compatible software which some companies and regular consumers do not have budgets for.