mysql improper privileges, a crash, or a shutdown by another method. code example

Example 1: mysql shutdown unexpectedly

So, before deleting files, first try to do what the error message in XAMPP 
message panel recommend you to do, using the MySQL backup folder which is 
included with XAMPP. So do the next:

Rename the folder mysql/data to mysql/data_old (you can use any name)

Create a new folder mysql/data

Copy the content that resides in mysql/backup to the new mysql/data folder

Copy all your database folders that are in mysql/data_old to mysql/data 
(skipping the mysql, performance_schema, and phpmyadmin folders from data_old)

Finally copy the ibdata1 file from mysql/data_old and replace it inside 
mysql/data folder

Start MySQL from XAMPP control panel

And, voilà. No databases lost, no ports changed, no run as administrator, 
no force recovery, no kill mysqld process, no restoring from previous versions,
no more errors.

Example 2: Error: MySQL shutdown unexpectedly.

go to Xampp and navigate to xampp/mysql/data directory
delete all files and dir
and paste files in backup directory