Try downloading the latest version 3 control panel that is linked in my signature.
Open the download archive file and then click on the CPv3 folder.
Then drag the files and folders into your xampp installation folder overwriting when asked.
Important to close any other version control panels before starting this latest version.
Now you will see perhaps a better log window with more detail and more general features.
Now you should click on the green tick in the MySQL Service column to remove the MySQL Windows service.
Once this has been achieved you should see a red X in its place.
You should then be able to start MySQL.
The Windows Service (Green Ticks) are not required for normal use of XAMPP, so you could remove them all and start the XAMPP components manually, the preferred method.