This one's is pretty much better. I'm using MS Office 2003.
At first, when I open an Excel Spreadsheet file to edit something and then open another one to copy or compare 2 files but the problem is they can be seen only by switching pages.
I found this trick and followed it step-by-step and now, i can open excel files as much as I wanted and they can be seen all of them without and switching pages.
See it HERE