Fonts don't work?

I know it's a little bit not related to icon making
but recently my PS is showing less and less fonts available for me to use

i've checked the c:windows/fonts
those fonts are still there, but i just can't use them
the list shown in my PS is really small now, can someone give me some help?
i'm really desperate! whenever my system is near to another breakdown, this will happen.
i really want a way to solve it, and plus i've deleted lots of files in my HD and have like 4 GB free which i could use all the fonts even if i only had 2 GB free
this is why i'm wondering, i have even more freespace but i still can't use the fonts?

thank you sooooooo much!!!!