system fonts messed up (solved)

[xfrank]

I have an annoying problem that I can't solve by myself, I need help from the experts of this forum. I opened a thread in the Mate subforum but despite the huge number (+300) of visits, nobody (except phy-thon) posted any advice to help: http://forums.linuxmint.com/viewtopic.php?f=219&t=147064 Maybe I opened it in the wrong subforum.
In few words, this is an issue with the system fonts: the default font of the system, instead of a sans, is a monospaced, probably Nimbus Mono L. I tried several fixes but nothing seems work. I've found in another forum a similar issue: https://bbs.archlinux.org/viewtopic.php?id=141809 but the guy with this problem dind't explained with details how to solve it.
This issue is very annoying, please help me to fix it.

[Fornhamfred]

If you go to software manager and type in fonts, the mscorefonts package will be listed. Install this and you should be able to reset the desktop fonts to suit you.

Right click on the desktop, change desktop background and amend the fonts.

[xfrank]

thanks Forhamfred! I reinstalled ms-fonts, but that was not the solution. I solved this issue today thanks an advice of py-thon. The problem was that I added some extra lines in the file font.conf, in this way the system was not able to read correctly the whole file.
As in many cases, a little change has huge effects.
Now my fonts are almost perfect. Much better than Windows.