Hello AlisonBurton,
I'm John an Independent Advisor and a Microsoft user like you. I'll be happy to assist you today. I understand you want to reinstall Windows Media Player. What is your current Windows version and edition? Press Start then click Settings(Gear icon), select System then About.
Kindly try the method below
Please try checking Windows Media Player at this location
C:\Program Files (x86)\Windows Media Player
Find and run wmplayer.exe
If this does not work, Press Start then search 'Manage optional features'
Click Add a feature
Select Windows Media Player then click Install
Please try opening Windows Media Player
Kindly let me know if this helps or if you have any further concerns.
Sincerely,
John DeV
Independent Advisor