DVDs are usually tied to specific regions. A Region 1 (US) disc won't play in a DVD drive configured for Region 2 (Europe). Windows allows you to change the region of your DVD reader, so you can use it to play a disc from a different location.
A heads-up before we start: you can only change regions a finite number of times (usually 5 times). After that, your DVD drive will be locked to its current region. You'll have no way of changing region again – even if you reinstall Windows or use the drive with another PC. It's also worth mentioning that some DVD playback software may disregard region locking altogether. Finally, not every DVD will be region-locked, although titles from major publishers almost always are.
Changing your DVD player's region is an option buried within Windows. Start by opening File Explorer with the Win+E keyboard shortcut. Navigate to the "This PC" screen using the left navigation pane.
Under "Devices and drives," find your DVD drive. Right-click it and select "Properties" from the context menu.
In the Properties popup, switch to the "Hardware" tab. Ensure your DVD drive is selected in the "All disk drives" list and press the "Properties" button at the bottom of the popup.
On the next screen, first press the "Change settings" button and then switch to the "DVD Region" tab. Here, you can view the current region and the number of region changes you have left. To change the region, select your country from the list and then press the "OK" button.
Assuming you still have some region changes remaining, Windows will apply the new region to your drive. You can now use it to play DVDs locked to the selected region. Discs from your previous region will no longer play with region-locked software.