Well. LFG is designed to replace blizzard's premade groups entirely just like custom raid frame addons (like grid, grid2, healbot) did towards blizzard's compact raid addon. We can actually do little customization towards Blizzard's UI unless we write our own "UI". Instead, just use LFG to create/search groups instead of blizzard's UI since it sucks.
Besides registry cleaner, it is also necessary to perform a defrag for your computer hard drive regularly, which is not only a good way to optimize your computer system's structure, but also can help you clean those fragments created in the incomplete program removal. There is a specific computer defrag utility available on the Windows operating system that enables the computer user to perform a defrag for the computer disk, or you can choose a free third party defrag tool like Auslogics Disk Defrag that opimize your computer disk in a quicker and more effective way.