Save it to your Personal Macro Workbook.
The easiest way to get there is to record a new macro and on the screen where you enter its name, hit the drop-down list under "Store macro in:" and select "Personal Macro Workbook". Then click OK, then stop the macro.
Then when you go into the VB Editor, you should be able to see your Personal Macro Workbook and you can store your code there and it will be available to you whenever you have Excel open on that computer.
At what point are you getting that message?How do I unhide a workbook? I says I have to do that to edit it.