Windows 2000 is still in widespread use, four years or so after the release of its successor Windows XP, according to market research firm AssetMetrix. And that is despite the end of mainstream support for the operating system from the end of this month.

The research report indicates Win2k remains widely deployed in corporates, and lost only four percentage points in popularity from 52 per cent in the last quarter of 2003 to 48 per cent at the start of this year. Over the same period, Windows XP rose in popularity from 6.6 per cent to 38 per cent. This fits in with earlier findings in April when AssetMetrix, which appears to make a substantial living from counting Windows PCs and therefore aiding and abetting Microsoft's upgrade programme, surveyed 136,120 PCs and found that 37.6 percent of them ran Windows XP.

The report also found that, while Windows XP is now the most popular operating system for companies with fewer than 250 PCs, Windows 2000 still has a greater than 50 per cent market share in larger organisations.

Microsoft mainstream support for Windows 2000 is due to expire on 30 June 2005, although it may be forced to extend it, as it did for NT in similar circumstances. After that, Win2k moves in extended support, which appears to rule out further service packs.

It's a situation that analyst Michael Cherry reportedly described as a disaster for those needing to manage large numbers of Windows PCs. Cherry advised companies to prepare for a move to Longhorn, XP's successor due next year, skipping XP altogether.

AssetMetrix director Steve O’Halloran said: "The findings of this study suggest that Windows 2000 still plays an important part in many IT environments, with organisations often choosing Windows XP to replace Windows 98 and Windows 95. Companies re-deploying PCs, without a policy to manage and support their operating systems, will have their Windows XP transition rate dictated by PC obsolescence rather than by intelligent planning and forecasting."

The study also found that Windows 95 and Windows 98 PCs reduced from a collective 28 per cent to under five per cent and Windows NT popularity fell from 13.5 per cent to about 10 per cent. The Windows 98 result shows a big drop-off from a report in December 2003, when AssetMetrix collected data on over 370,000 PCs from 670 businesses in the US and Canada and found that 80 per cent had at least one PC running either Windows 95 or Windows 98.