Microsoft has quietly extended a free upgrade offer that will allow some buyers of Windows 10 S to move to Windows 10 Pro, a move that suggests buyers aren't entirely happy with the cut-down version of Windows restriction on running apps sourced from beyond Microsoft's own Store.

Windows 10 S is a cut-down version of Windows that behaves an awful lot like Chrome OS.Microsoft launched the product in May 2017, suggesting it would be a fine laptop for mass deployments in schools or perhaps even in businesses that don't need full desktops for some workers.

The OS comes with restrictions: you can only load apps from Microsoft's own Store and Edge is the default browser. Even if Microsoft's store admits other browsers, Edge or IE will remain the default apps for opening .htm files. Bing is the default search engine in Edge and IE and there's no option to replace it.

Microsoft justified those restrictions by saying they help keep Windows 10 S easy to administer and use. But it also said users who can't get the apps they really, really need in its store could upgrade to Windows 10 Pro, for US49. Buyers of Microsoft's own Surface Laptop, a device at the higher-end of 10 S devices, were given until December 31st, 2017, to upgrade gratis.

And now, in an obscure blog post announcing the availability of coloured Surface Laptops outside the USA, Microsoft's quietly extended the free 10 Pro upgrade offer until March 31st, 2018.

The reason? “We hope this provides increased flexibility for those people searching for the perfect back-to-school or holiday gift.” Which after a shove through the El Reg's marketing-to-English translat-o-tronic sounds a lot like “We're extending the free offer because buyers have figured out being tied to our app store, Edge and Bing is a deal-breaker and they either buy Chromebooks or someone else's Windows machine. Or, God forbid, a Mac.”

None of the non-Surface-buying outcomes above interest Microsoft much. Hence, we conclude, the extended change.

Analyst firms rate Chromebooks one of the few bright spots in an otherwise moribund PC market, but to date The Register has encountered no mention of Windows 10 S exciting buyers to the extent that machines running it make a dent in market share statistics. If that changes, we'll let you know. ®