I'd use the official Microsoft Windows Installer Cleanup Utility first if for no other reason than to see if WLE is even listed. I'd also get it from the Microsoft TechNet site: Free Utility: Windows Installer CleanUp Utility
My concern is this tool was last updated in 2008 but since it works on only the Windows Installer configuration it might be better than the brute force removal used by Revo. As the instructions state: "...you would resort to this utility if you can't uninstall or update an application through Add/Remove Programs or other methods. By deleting the Windows Installer information, you should be able to reinstall the application. You can then leave the program installed as is, update it, or even remove it." All of this presupposes that WLE is actually listed in the Cleanup dialog box. If it isn't, I'd then definitely go with Revo.