I'm using Windows 7 - 64 and here is what I've done to put an end at this problem:
1. I've copied and pasted the folder C/: Windows/fonts on the desktop
2. selected all the files inside the copied folder with ctrl+a
3. and then right click and select install
4. A message box will appear saying that some fonts are already installed and asking if you want to replace them. Tick the option "do the action for all the elements" and click yes.
Then this problem should be solved.
Thanks B Noir for your help!