font appearance problem

I don't know how,, but since yesterday the font isn't anymore bold in two
places :
- in the start where is displayed "all the programms" and then when you
click on "previous" with the arrows, used to be bold
- in the windows that opens when you copy or move files, the places from
where to where you move the files and the files names also used to be bold

it seems to me that this happenned after i used the desktop remote to pilot
a computer of my network but i m not sure, it could also be any gadget i
installed, but anyway the problem is that not any option in any menu let me
to get this back as usual, i tried lot of things and this is getting me
crazy, not so much for the start menu but the second thing for the windows of
compying, this was very helpful to have the names in bold.

I can't stand when something goes out of control like that, so please
someone help me...