Strange problem with Arial font

[Lisa]

Hello,

I'm having an odd problem with my fonts in Outlook and Word. When I use
Arial it will only appear in Bold. I haven't selected bold and I can't get
rid of it. When I checked Format/Font from the menu options I noticed that
the dialogue box doesn't have an option for "Regular" under the "Font Style".
It seems to be the only font that doesn't have this option. I checked in the
WINDOWS/Fonts folder to see if there was a font in there called Arial, and
there is, it's called "arial.ttf".

Does anyone know how I can fix this?

Thanks,
Lisa