MS Excel: Automatically open a Form when spreadsheet is opened in Excel 2003/XP/2000/97
There are several "events" available within an Excel spreadsheet where you can place VBA code. In your case, we want to open the form when the "Workbook_Open" event fires.
To do this, press Alt-F11 to go to the Visual Basic editor.
Then select ThisWorkbook in the left window. In the right window, select Workbook in the first drop-down and Open in the second drop down. Then enter the following VBA code:
Private Sub Workbook_Open()
UserForm1.Show
End Sub
Now when the spreadsheet is opened, the form "UserForm1" will automatically open.