uninstall left over files

Revo Uninstaller Pro can removed leftover files, click on the "Traced Programs" and type the name for the programs you uninstalled and it will scan for leftover files and registry entries and you can delete them. I would recommend you to uninstall programs from Revo directly next time.

Note: You will only see "Traced Programs" in the Pro versions.

Revo Uninstaller/Ashampoo Uninstaller

There's no such uninstaller that can completely remove all the left over including Revo Uninstaller, Ashampoo etc.... The obvious proof is if you install a 30 day trial application. After the trial has expired, try to uninstall then re-install to see if you get another 30 trial.

The only people that can remove the left over are the people who actually wrote the software. And they put hidden entries with special permission in the registry that no uninstaller software can detect.

So just in case you are trying to use a 30 day trial software and hope to use one of those uninstallers to get another 30 day trial then you are out of luck. The only way it would work is before installing the trial software, make a backup image then after 30 days, restore the image then re-install it. However, there's no such thing as 100% fool proof. Smart hacker can use Process Explorer from MS Sys Internals to trace every move of registry Read/Write and delete them.

NOTE: I am not saying that this is what you are trying to do, just one of the scenerio. Personally, I use revo uninstaller and it's pretty good to clean the left over compare to the native Windows installer but not all.

To purge a system of a program, you need a desktop search tool like UltraSearch that scans the MFT for everything. Deleting stuff using this tool can be dangerous and cause errors if you are not an advanced user, because it will show .dll and .ocx files that must be unregistered first or you start getting errors or you can break your system if they are part of Windows(stay away from the WinSxS folder too). For the registry there is a Find & Find next(F3) only remove the main program folders under HKEY LOCAL MACHINE software.

You can use this Microsoft Fix-It tool on a one-time basis each time you do a bunch of un-installs -
https://support.microsoft.com/en-us/mats/program_install_and_uninstall