I dont install HitmanPro but use it as one time use.

So why it appears in program files & add/remove?

I had that issue years ago. Don’t remember the resolve.
You should be able to get an answer from sevenforums.com or Microsoft.com, it is a windows issue.

I uninstalled it & the whole folder was deleted in which I had HitmanPro?? The folder had all testing tools like CCE, Kaspersky TDSS & other softwares. I lost all the softwares.