Only 11 per cent of companies surveyed by research firm Vanson Bourne have already made the migration to the system released in October 2001.
The most common reasons for companies not making the switch -- cited by 45 per cent of respondents -- are concerns about the complexity of the roll-out process and the demands it would put upon already stretched resources within the IT department.
The second most common reason for XP-avoidance was a concern over the ability of existing infrastructure to support the operating system. Forty per cent of companies were worried about the initial investment they would have to make just to make their network XP-ready.
A spokeswoman for Microsoft said: "The majority of our enterprise customers in particular are licensed to run XP, but the size of these organisations is such that it may well be the case that only 11 per cent are fully migrated.
"Feedback from some of our larger customers is that complete deployment in their organisations may take several years just because of the scale of the number of desktops."
However, the spokeswoman believes that replacement cycles are about to swing in Microsoft's favour. She said: "With hardware refresh cycles lengthening to three-and-a-half years from an average of 18 months, this is a significant reason for the delay. However, significant hardware investments were made for Y2K and we are now reaching a point where customers are needing to consider updating this inventory."
Rob Drew, strategic partner and alliances manager at software management firm ON Technology, who commissioned the research, said: "I'm not surprised that companies are worried about the time needed to complete a roll-out as most of them are still using manual roll-out processes. Sending an IT person to each desktop simply to upgrade the operating system is much like getting people to hand deliver letters rather than using the post.
"It isn't XP itself that people are worried about, it's time and cost that is preventing them from migrating."