I've answered you what to do in another topic about not being able to run installers:
Try closing all background processes before running the installer.
Or if you have a newer Windows version just find the installer executable in task manager and click "Analyze wait chain" and just kill whatever process is holding it up.
That's not from Microsoft, yes. There's a way to do the analyze wait chain thing in process explorer if your version of Windows' task manager does not support that option.
And your reply was the super-vague
And since you never detailed what part of my instructions you were having trouble following, I gave up on helping you.
Edit: Actually seems like Process Explorer can't do Analyze Wait Chain, at any rate: