It appears that Install manager only keeps track of what is installed as long as long as you don't delete the downloaded files. Once you install and delete the .exe they disappear from Install manager where it said installed.. Why cannot Install manager check where it installed the files to for a better understanding of what is installed or not installed.

That's a good idea. Why not put it in the +++ Band-in-a-Box Wishlist +++ so more people will see it, discuss it and possibly support the idea.

I would support that also. Sometimes with a new start of the install manager, it knows it has the files available (already downloaded), but doesn't seem to know that they have already been installed.