A file with a .VOB extension is an old video file format that was used in the days of the DVD player. Since the VOB format is based on the MPEG file format, the Windows system cannot open it by default because special codecs are needed, which are available in third-party players.
VOB file format
If you use Windows XP, Windows 7 or Windows 10, you need to install a player or codec set that has support for the VOB format. Here’s a list:
K-Lite Codec Pack
VLC media player
Note: With the K-Lite Codec Pack, you can play the .VOB files in your standard Windows player. If you want good quality and a different player, VLC media player is a good choice.
Translated with www.DeepL.com/Translator (free version)