This is an often asked question.
What you need to understand is that one does not install fonts directly into a program these days (unless your program uses proprietary fonts, such as Gerber or SignLab). If it is TrueType (TTF), Type 1 (PFB/PFM) or OpenType, it installs into your OS. One installs the fonts into the operating system so that all programs can use them. In your case,
Windows is your operating system.
Never, repeat never, drag and drop fonts to install them. They must be installed as given in the two answers above this post or you will have registry problems down the road.