There were some such devices, running Windows, in the mid-2000s. Larry Augustin (Sugar CRM, VA Research) was associated with one start-up during his time at Azure Ventures.

Found the (ex)-firm: Oqo.

https://www.ft.com/content/5241d778-56d5-11da-b98c-00000e251...

https://en.wikipedia.org/wiki/OQO

https://www.slashgear.com/ces-2009-oqo-model-2-umpc-hands-on...

http://cf9e233f57bd4ae986b3-d4e74cbd2619c9a623339399e96f346b...