Updated This story was updated on Thursday 25th October 2007 23:21 to add comment from Microsoft.

Something seems to have gone horribly wrong in an untold number of IT departments on Wednesday after Microsoft installed a resource-hogging search application on machines company-wide, even though administrators had configured systems not to use the program.

"The admins at my place were in a flap this morning because Windows Desktop Search 3.01 had suddenly started installing itself on desktops throughout the company," a Reg reader by the name of Rob informs us. "The trouble is that once installed, the indexer kicks in and slows the machines down."

The blogosphere is buzzing with similar reports, as evidenced by postings here, here and here.

"I'm slighly pissed of [sic] at M$ right now," an admin in charge of 3,000 PCs wrote in a comment to the first aforementioned link. "All the clients have slowed to a crawl, and the file servers are having problems with the load."

According to Reg tipster Rob, Windows Server Update Services (WSUS) forced Windows Desktop Services (WDS) 3.01 on the fleet of machines even though admins had configured their system to install updates only for existing programs and the search program wasn't installed on any machines (well, until then, anyway).

Bobbie Harder, a product manager for WSUS, denied the WDS update was unauthorized, saying it was applied only if administrators had approved a previous desktop search install in February.

"The initial update would have only been installed if the update had been either auto, or manually approved, and if the applicability criteria was met on the client (that WDS was installed)," he wrote in a blog post here. "With the expanded applicability rules, and the WSUS default setting to auto-approve new revisions, it may have appeared as if this update was deployed without approval. The initial version of the update would have had to have been approved, and the 'auto-approve revisions' option on (by default) in order for this revision to have also been approved and deployed."

Lest readers think Harder was saying the snafu was the fault of admins, he went on to say engineers would work to make auto-approval behaviors "more predictable and of similar scope as the original approved updates, as we appreciate the confusion this behavior caused."

It's been a rough several weeks for managers running Microsoft's auto update services. Last month, bloggers disclosed the existence of a Windows patch that silently and automatically installed itself even on Machines configured not to install updates. Critics cried foul on the principle that users should have absolute control over their machines. They also argued that the stealth update could hamper compliance requirements.

Microsoft said the patch was installed on machines only to make sure Windows Update worked properly in the future. Managers promised to be more transparent in the future.

The revelation that Microsoft is pushing yet more installations not explicitly agreed to by administrators is not likely to sit well with this same vocal contingent. Redmond may want to don the asbestos suits now. ®