Windows XP is like the older Windows 7. XP is the another operating system from Microsoft. You can make an estimate about XP’s popularity by that 400 million copies of XP was sold with in 5 years from the when it became available.
About 1 billion copies has been sold till Apr, 2014. Its only Windows 7 which has surpassed the usage of Windows XP.
Extended support for XP ended on Apr 8, 2014. From this day Windows XP is not receiveing any security update.
Previously its market share was quiet decent. Still now 13.57 % of computer users prefer Windows XP. But the use of Windows XP is decresing day by day