My particular reason for updating to Pro, is the ability to see and hence uninstall 64 bit software and the ability to monitor new software installation, record the changes and use the for un-installation.  The full list differences between the two are at:  http://www.revouninstaller.com/revo_uninstaller_free_download.html

Note: !! DO NOT download from the above link !!   

To get the 50% discount, carefully follow the following steps:

#1.  Visit:  http://windowssecrets.com/

#2.  Login at:  http://windowssecrets.com/  and click on the "Newsletter Archives" Tab.

#3.  Look down the list and click on:  "2011-09-08 305 Certificate cleanup for most personal computers".

#4.  Just below the "Windows Secrets Newsletter" header, there should be a "Revo Uninstaller Pro" advertisement.  Click on: "Uninstall any unwanted program easily".  If you can't see the "Revo Uninstaller Pro" advertisement, make sure that "AdBlock" or "AddMuncher" or other add blocking program is turned off for that page.

#5.  On the resulting page, click on the "BUY NOW -50% OFF" button.

It should show a price of $19.62 plus any applicable taxes.

After paying, you will get the usual email (check spam mailboxes etc.), you will get a download link and authorization code.

I have installed without uninstalling the free Revo Uninstaller.  They are in different folders.

Enjoy!