Macro Security Warning
 

I've written some extensive macros into a worksheet in Excel 2003, back when
I was on XP. Now that I've moved my copy of Excel to my Vista machine, I get
"this author has not been authorized..." message. I've se security to medium
( I DO want security on), but when I open the file, the check box where I
should be able to "Always trust macros from this source" is grey so I can't
check it. I' ve also tried to add myself to the Tools/Options/Security/Macro
Security/Trusted Sources but I can't seem to find a way to add myseld as a
source. the only option is t "Remove" (Even though there are no trusted
sources listed).
What's my next step?