IT managers are ignoring Microsoft's advice to move rapidly to install Service Pack 2, and are treating SP2 as a new operating system rather than just an upgdate to Windows XP.
The update aims to improve Windows' security - and Microsoft's reputation - through extensive changes to Windows XP's default settings, new tools and a new patch management system. But businesses are putting SP2 through a more rigorous testing procedure than usual with upgrades because of the scale of the changes, which Microsoft has admitted are likely to break many existing applications.
"We are treating this as an OS upgrade," said an IT director at a major international IT company.
Although Microsoft has released SP2 to manufacturing, which marks the completion of the software, it may be months before even the most adventurous of users sees it on XP's online update feature, free CDs or new PCs. Enterprise users will probably receive the update from their company's own servers through a centralised installation process.
Enterprises face the longest process for getting SP2 up and running, and will be first in line for the software, starting from next week. Most PCs will not need SP2's full 256Mbytes - those with SP1 and up-to-date patches, for example, will need less updating.
Microsoft said XP Home Edition installations would face an 80Mbyte average download, while XP Professional desktops would average 100Mbyte. The download will be 20Mbytes bigger for PCs without SP1 installed.
Microsoft is urging users to switch on XP's Automatic Update feature, which downloads patches in the background, and expects to distribute SP2 to about 100 million PCs via this method in the next two months. Users who want to download manually will be able to do so by the end of August. New PCs with SP2 preloaded are expected to appear in September and October. Users outside North America can expect to wait longer.
Microsoft describes the service pack as a quantum leap in PC security and is urging consumers and businesses to roll it out as soon as possible.
"This is not about fun and games," said Microsoft's Barry Goffe. "SP2 is about improving the security of our customers' infrastructure."
However, IT managers are in no hurry. IBM told workers not to download SP2 until compatibility testing had been carried out. And Sophos Antivirus said while it expected SP2 to improve security, it had no immediate plans to deploy it internally.
"It's just not something we consider a very high priority presently," said a Sophos spokesman, "and we will only roll SP2 out when we are confident the time is right and we can do it properly."
Another major IT firm said it would run extensive quality assurance first. "There will be some inevitable compatibility issues that are missed in QA," said the company's IT director. "There will also be issues with the SP2 itself and we fully expect Microsoft to follow up with fixes."
Many companies say they would like the benefits promised by the service pack, but haven't yet switched to XP anyway. Sophos said it had very few XP PCs running in its UK headquarters.
"We're still putting Windows 2000 on all new computers and we're not about to change to XP any time soon," said a tech worker at another company.
Matthew Broersma writes for Techworld