Now open the folder where you previously saved your TTF file for the font which you wanted to install.... Simply drag and drop it in the Font folder that you opened via control panel and it'll automatically start installing it.
Go to your fonts folder (C:\Windows\Fonts) and select the fonts you want to retrieve from the folder. As you have noticed, you cannot drag and drop or copy these files from there as you would from any other folder.
When using Install, fonts will go into %LOCALAPPDATA%\Microsoft\Windows\Fonts\ rather than c:\%windir%\fonts. If you want to see where a font is installed to, navigate to Control Panel\All Control Panel Items\Fonts, find a
Please use the Win-7 keyboard-shortcut [Windows + E] and in the address bar [ALT+D] enter the address: shell:fonts or %WINDIR%/Fonts (C:\Windows\Fonts)! and you can see all installed fonts, in Windows 7 fonts (... see Image-1 Arrow-1).
Go to C:\Windows\Fonts or your own Windows drive and make sure you have deleted the fonts you don't wish to be there in case you have installed new unwanted fonts.