How to setup WYSIWYG editor in admin section?

First download WYSIWYG Module and install it from Administer -> Site Building -> Module section.

Now go to the Administer -> Site Configuration -> Wysiwyg

When you click on it, you will see the following screen:

Here you will see a link TinyMCE (Download)

Click on it and download TinyMce editor and keep it the following location:

Extract the archive and copy its contents into a new folder in the following location:
sites/all/llibraries/tinymce

So the actual library can be found at:
sites/all/llibraries/tinymce/jscripts/tiny_mce/tiny_mce.js

Once, you do the above, you will see the another screen look likes:

select tinymce from dropdown for both the dropdown and then click on SAVE button.

and done your editor is now working...

Enjoyin Drupaling

Cheers!