Microsoft's Windows 8.1 operating system has overtaken its older sibling Windows 8 for the first time in terms of internet usage worldwide, according to StatCounter, the independent website analytics company. The company's research arm, StatCounter Global Stats also finds that despite Microsoft's ending of support in April this year, Windows XP refuses to die and remains the world's second most popular operating system version. However, for the first time globally, the combined total of Windows 8 and 8.1 (14%) overtook XP (12.9%) in August.StatCounter finds that Windows 8.1 worldwide has grown steadily to 7.5% in August ahead of Windows 8 (6.6%). The newer operating system overtook its sibling in the UK in April and in the US in May. The data covers desktop, tablet and console.

"Following a mixed reaction to Windows 8, perhaps because of its radical new look, Windows 8.1 appears to be winning over users," commented Aodhan Cullen, CEO, StatCounter.

However, he added that the stubborn refusal of Windows XP to retire almost five months after the ending of non-paid support is a concern in terms of security and virus risks for remaining users.

Globally XP is on 12.9%, behind Windows 7 on 50.3%. In the US, XP internet usage share has declined below double figures to 8.9%. Europe's XP share is 10.6% with UK down to 5.2%. Individual country stats are available here.