If you live outside the US and installed Windows 10 Technical Preview, you may be disappointed when Microsoft's new virtual assistant Cortana greets you with following message:
I'm afraid I'm not available to help in your region.
Hopefully Cortana will be supported in a variety of regions and languages on release, but as of now it only works in the US. Since it's pre-release version of Windows we can't really complain about this too much... Still, if you want to try Cortana outside of the US, you can do this by changing your region and language settings.
Go to Control Panel > Clock, Language and Region click on Change Location and set Home location to United States
Next go to Control Panel > Clock, Language and Region click on Change input methods and add English (United States) as your primary language.
And now go ahead and have some fun with Cortana!
Windows 10 Technical Preview Build 9926