Try the following steps and check the result.
Step 1: Change DVD region
a. Click Start (or Search), type devmgmt.msc and hit enter to open Device Manager.
b. Double-click DVD/CD-ROM drives, right-click the DVD drive you want, and then click Properties.
c. On the DVD Region tab, make the changes you want.
Note: To configure your DVD drive to play discs from other regions, select a geographic area from the list of regions. Typically, you would select the region in which you reside. It is not usually necessary to change the setting again.
Important: The region settings can be changed only a limited number of times. When Changes remaining equals 1, and you select a new region, an alert will be displayed warning you that after this, you will only be able to play DVDs from that region. Be aware that you might not be able to change the region setting for some DVD hardware and software decoders.
Step 2: If the issue persists, run Windows Media Player DVD troubleshooter and check the result.