I've installed several Keil version's and there are multiple bcakups, different versions which are not required now. Before installing new KEIL version V5.27 I wanted to uninstall all other previous versions. but my uninstall.exe is not working at all. is there a different method, through which. I can uninstall these old keil.
Maybe you did have a 2ndary virus on your computer. I haven't seen that pop up before when I unistalled the tools.
You might want to try these steps
https://www.thewindowsclub.com/operation-did-not-complete-successfully-because-the-file-contains-a-virus
or go to your IT department and have them check the computer.
Make sure you have proper admin privileges on your machine.
Also, you could always just delete the c:/keil_v5 folder, and install a fresh copy of keil. The tools don't put mch in the registry, so it shouldn't cause any headaches.
If all else fails, and If you want to remove the Keil entries from the add remove programs view, you may have to remove them from the registry. Make sure to backup your registry and check with an IT pro first.
See also support.microsoft.com/.../program-is-not-listed-in-add-remove-programs-after-installation