I have installed 5 PCs recently with Excel 2007. One PC is having problems in
that it cannot change any colors for fonts in a cell or for the cell's
background. Likewise it seems to have problem switching to some fonts, but
not to other for the text.

We start up with a blank worksheet, just type in some text in a cell or two,
and then cannot change colors at all - it remains black text at all times. If
we go to print preview (for a laser) it does show the cells as highlighted in
gray, but no font gray differences. So what might be going on with the
display however?

The person messed around with Windows Themes (XP) and wih Excel Themes, and
this is when the problem started. But I see nothing out of the ordinary.

So a) is there a way to reset ALL Excel defaults, and b) what might cause
this behavior (what can I look for)?

Thanks for any help.