You may have it as an option (likely press the “advanced” button from the settings tab of the display control panel, and look for something like monitor orientation, or monitor rotation in the special tab for your gfx adapter) where you can select either “landscape” or “portrait” for the screen rotation. You want landscape.
Most gfx adapters have this “feature”, and like GL, I have never been able to work out why? Maybe there’s people who set up a custom desktop so it can be read that way round, and like to have their start button slide a list out from the top left? Seems like an awful lot of effort though, and all the programs would still be sideaways…:you_crazy
That it’s still there is likely down to microsoft, and the bloated code that makes up windows though – been part of the direct x or GDI API code since the year dot (and was put there for some obscure reason that no-one remembers), and gfx card manufacturers just implement it because they can do easily, and it’s part of the WDM certification hoops that need to be jumped through for any driver.
