Its permissions stuff. This can be avoided if you have two separate drives. If not, its good to try to install games away from the programs folder unless its more uh, legit games. If you all you have is one drive, try throwing all your uh, "downloaded" games in like C:\games\
If that still does not work, do this:

type in "C:\Users\Your_user_name" in folder explorer or in the box that pops up when you hit the windows key + R and click OK.
If you do not see an 'AppData' folder, go to the VIEW tab above the location bar, select 'view file extensions' and select 'view hidden items' Then you should see folders. I would do this in C:\ drive as a whole but that is up to you, in fact I would do EVERYTHING below in C:\ as this would cover every single folder within the C drive but that is me.
Right-click on the AppData folder and open the Properties.
In the next window, go to the security tab and click on Edit.
Click on Add.
Now, type Everyone, click on Check Names, and finally, hit OK.
Click on Everyone and allow Full control under Permissions for everyone. Click on OK.
If that doesn't work, you can download a program that allows you to take ownership of folders, its called "Take Ownership" and once installed, you can just right click on folders that won't give you write permission and you select "Give ownership" and it should do the trick as well.

woah! no need for slurs.