You have the latest XAMPP installer downloaded and installed.
You have Installed XAMPP to C:\Users\User\XAMPP directory
The Command Prompt is your best friend
We’re going to upgrade HTML_Common and Install HTML_QuickForm_advmultiselect
cd\Users\user\xampp\php pear upgrade HTML_Common pear install HTML_QuickForm_advmultiselect
That’s all there is to it!