Excel:VB properties window will not open; project explorer is ok
 

I am an instructor in Excel so I should know this but I'm stuck. I'm using
Excel 2007 and in Visual Basic I can get the project window to open fine but
the Properties window absolutely won't open. It used to so I must have
accidently did something that caused this to happen! I want to change the
name of a module. Anyway, the view menu won't open it; F4 won't open it. Any
ideas? I do have 2 monitors and I'm wondering if it is lost somewhere between
the 2 but no idea what to do about it. Thanks.