Trying this place out for the first time since Stack Overflow never allows my posts to stay up.

Yesterday, I installed XAMPP in C:\XAMPP. The XAMPP Control Panel warned that Port 80 is being used by other apps so I used the config and changed Apache(httpd.conf), changing:

The warning went away, because port 81 is not being used by any other processes. I installed WordPress inside c:\xampp\htdocs\blog and found that I accessed it by running http://localhost:81/blog.
Everything was working fine until I decided to investigate getting it to run from port 80 instead. I stopped all services that use port 80 and set Listen back to 80. So that would be mean I only need to type http://localhost/blog to access WordPress instead of http://localhost:81/blog, right?
 But the browser would wait a while being returning a page loading problem for http://localhost:81/blog. 
 Now I have tried uninstalling XAMPP, deleting the entire XAMPP directory (including Apache) and then reinstalling XAMPP (including Apache). It now has a completely new database. After doing this, these things happen:
 "http://localhost" will run c:\xampp\htdocs\index.php just fine.
 "http://localhost/blog02" will run c:\xampp\htdocs\blog02\index.php just fine.
 "http://localhost/blog/test" will run 

 How in God's Green Earth can this 81 port remain when Wordpress, Apache and XAMPP have been completely wiped?!? Do I have to wipe my machine and reinstall Windows to regain control of my Apache ports?


 Any references that can direct me on why this happens would be greatly appreciated. I'll be cleaning up broken crockery in the meantime.