A mechanism used to temporarily disable Windows XP SP 2 will now be available until next February, Microsoft Corp. said, after which period Windows XP SP 2 will be delivered to all machines running Windows XP or Windows XP with SP 1.

The delay extends Microsoft’s original 120-day window, introduced on August 16, via a tool that helped prevent users downloading and installing SP2 via Windows Update and Auto Update.

Microsoft is reacting as major customers, including IBM Corp. and Hewlett Packard Co., delayed plans to roll out the service pack across their own desktops until it had been tested for compatibility – IBM, for example, noted incompatibility between some of its own business applications and Windows XP SP2.

Microsoft itself, meanwhile, published a list of 200 applications that it said may behave differently with installation of the service pack.