Microsoft has been forced to acknowledge a major conflict between a recently distributed critical Windows security patch and some Hewlett-Packard software. KB908531, released on April 11, addresses an issue whereby a critical security hole in Windows Explorer could give a remote attacker complete control of a user's computer. Installation of the patch by many users prompted reports of problems such as Office and IE lock-ups. Microsoft has investigated, and has confirmed that the problem lies in a conflict between the patch and HP's Share-to-Web software. The company has promised to release an update that will resolve the problem.

For the most part the glitches result from problems with some Hewlett-Packard software products, including any HP DeskJet printer that includes a card reader, HP scanners, some HP CD-DVD players/burners, and HP cameras, Microsoft said.

The problem is primarily affecting consumer users and is having "little to no impact on corporate networks," Microsoft Security Program Manager Mike Reavey wrote in a posting to the Microsoft Security Response center blog over the weekend.