There’s 2 approaches for this:

Restore the application window, then manually resize it to occupy both monitors, but DO NOT maximize it as it will go back to one monitor only. Then open up the spreadsheets and put them side-by-side.

This is the cleaner approach. You can open one spreadsheet first, maximize it to one monitor, then go to the Start Menu and hold SHIFT while clicking the Excel shortcut. This will call a second instance of the application, and you can maximize it to the second monitor. Then manually open the file.

The first approach has a nice feature attached to it which is the possibility of scroll-locking between spreadsheets, so if you’re comparing/editing data in two similar spreadsheets, makes it a bit easier.

Awesome hack, my office productivity just increased by 10%.

Comparing excelsheets is a bliss now, so some much easier…

Microsoft should hire you for usability testing and enhancement… those developers sucked in that area.

I had the original method of changing the settings via the application associations working on Windows XP but have recently switched to Windows 7 where this no longer seems to be an option.

I have therefore been searching for a method to use on Windows 7 and have found a number of suggestions like this which have led me to the blank screen issue. Adding a few snippets from various site led me to creating the following .reg file which works perfectly:

To use it, copy the contents below and paste it into notepad. Save the file as:

Excel 2007 Dual Screen.reg (Make sure you select "All Files" from the file type drop down).
Exit Notepad and run the file, accepting the warnings and your good to go.

Windows Registry Editor Version 5.00

; ----------------- This file is intended to allow dual screen working in Excel 2007 ONLY -----------------
; ---- It will not work for earlier version of Excel and modifies the registry so please use carefully ----

; Changes the /e to "%1" in the default and command keys to fix the issue that stops Excel opening .xls files

[HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\command]
@="\"C:\\Program Files\\Microsoft Office\\Office12\\EXCEL.EXE\" \"%1\""
"command"=hex(7):76,00,55,00,70,00,41,00,56,00,36,00,21,00,21,00,21,00,21,00,\
  21,00,21,00,21,00,21,00,21,00,4d,00,4b,00,4b,00,53,00,6b,00,45,00,58,00,43,\
  00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,74,00,57,00,7b,00,7e,00,\
  24,00,34,00,51,00,5d,00,63,00,40,00,49,00,49,00,3d,00,6c,00,32,00,78,00,61,\
  00,54,00,4f,00,35,00,20,00,22,00,25,00,31,00,22,00,00,00,00,00

; Deletes the ddeexec key and sub keys to stop Excel using DDE to open the .xls files

[-HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\ddeexec]
[-HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\ddeexec\application]
[-HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\ddeexec\topic]

; Changes the /e to "%1" in the default and command keys to fix the issue that stops Excel opening .xlsx files

[HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\command]
@="\"C:\\Program Files\\Microsoft Office\\Office12\\EXCEL.EXE\" \"%1\""
"command"=hex(7):76,00,55,00,70,00,41,00,56,00,36,00,21,00,21,00,21,00,21,00,\
  21,00,21,00,21,00,21,00,21,00,4d,00,4b,00,4b,00,53,00,6b,00,45,00,58,00,43,\
  00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,74,00,57,00,7b,00,7e,00,\
  24,00,34,00,51,00,5d,00,63,00,40,00,49,00,49,00,3d,00,6c,00,32,00,78,00,61,\
  00,54,00,4f,00,35,00,20,00,22,00,25,00,31,00,22,00,00,00,00,00

; Deletes the ddeexec key and sub keys to stop Excel using DDE to open the .xlsx files

[-HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\ddeexec]
[-HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\ddeexec\application]
[-HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\ddeexec\topic]

If you want to restore to the original, copy the contents below and paste it into notepad. Save the file as:

Excel 2007 Restore Settings.reg (Make sure you select "All Files" from the file type drop down).
Exit Notepad and run the file, accepting the warnings and your good to go.

Windows Registry Editor Version 5.00

; ------------ This file is intended to restore the defaul opening settings in Excel 2007 ONLY ------------
; ---- It will not work for earlier version of Excel and modifies the registry so please use carefully ----

; Restores all the settings for .xls files

[HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open]
@="&Open"

[HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\command]
@="\"C:\\Program Files\\Microsoft Office\\Office12\\EXCEL.EXE\" /e"
"command"=hex(7):76,00,55,00,70,00,41,00,56,00,36,00,21,00,21,00,21,00,21,00,\
  21,00,21,00,21,00,21,00,21,00,4d,00,4b,00,4b,00,53,00,6b,00,45,00,58,00,43,\
  00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,74,00,57,00,7b,00,7e,00,\
  24,00,34,00,51,00,5d,00,63,00,40,00,49,00,49,00,3d,00,6c,00,32,00,78,00,61,\
  00,54,00,4f,00,35,00,20,00,2f,00,65,00,00,00,00,00

[HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\ddeexec]
@="[open(\"%1\")]"

[HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\ddeexec\application]
@="Excel"

[HKEY_CLASSES_ROOT\Excel.Sheet.8\shell\Open\ddeexec\topic]
@="system"

; Restores all the settings for .xlsx files

[HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open]
@="&Open"

[HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\command]
@="\"C:\\Program Files\\Microsoft Office\\Office12\\EXCEL.EXE\" /e"
"command"=hex(7):76,00,55,00,70,00,41,00,56,00,36,00,21,00,21,00,21,00,21,00,\
  21,00,21,00,21,00,21,00,21,00,4d,00,4b,00,4b,00,53,00,6b,00,45,00,58,00,43,\
  00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,74,00,57,00,7b,00,7e,00,\
  24,00,34,00,51,00,5d,00,63,00,40,00,49,00,49,00,3d,00,6c,00,32,00,78,00,61,\
  00,54,00,4f,00,35,00,20,00,2f,00,65,00,00,00,00,00

[HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\ddeexec]
@="[open(\"%1\")]"

[HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\ddeexec\application]
@="Excel"

[HKEY_CLASSES_ROOT\Excel.Sheet.12\shell\Open\ddeexec\topic]
@="system"

Thanks muchly Britt! Please don't keep hacks like that to yourself!

To Sam ott: Check that the %1 is in quotes "%1"

Thanks for your work on creating this useful little tool. The .bat file method definitely works around the issue of opening separate Excel documents in separate Excel instances, without having to use the 'ignore other applications that use DDE' [in Office 2007] (which causes the problem of opening a blank Excel instance when double clicking a file). However, there is one little quirk of this methodology which users should be aware of;

By opening the files in separate instances of Excel, you inhibit the ability to copy formulas from one spreadsheet to another. For example if you enter the formula =sum(A1:C10) into a blank cell which gives a hypothetical total of 30 (value of 1 in each cell), when you copy this cell and paste it into a sheet in a separate instance, you will only copy the formula total, and not the formula itself (i.e. 30, and not =sum(A1:C10)).

Not as annoying as not being able to open separate files in separate instances, but well worth mentioning if you plan to copy large numbers of complicated formulas from one spreadsheet to another.

/chuck

p.s. sorry for the verbose comment

When I try to open an excel file from Windows Explorer… The app opens but there is no spreadsheet inside?
Also noticed that it has taken away the xcel icon and shows a small white box.

This really helped. I had to change the directory a bit, but after that it worked fine!