The shortest answer
Start with Leawo Blu-ray Player if you need a free Windows option. Download it only from the official vendor page.
If the PC has no Blu-ray-capable optical drive, software alone cannot read the disc.
Why VLC is not the default
VLC is excellent for many unprotected media files. Commercial Blu-ray movie playback can involve menu and protection limitations, so this site does not present VLC as a one-click replacement or provide bypass instructions.
Before installing anything
Confirm that the drive says Blu-ray or BD, identify whether the disc is standard Blu-ray or 4K UHD, and test with a known-good disc. These checks prevent a software download from masking a hardware problem.
Free does not mean identical
A free player can include upgrade prompts, advertisements, or fewer home-theater features than a paid option. The current research edition has not independently measured those behaviors.