What are Excel instances, and why is this important?

This article explains a little about what Excel instances are, how this affects Excel functionality, and how you can control it.

If you press Ctrl+Alt+Delete, start the Task Manager, and open the Details tab, you may see one or more Excel.exe listed here.

Each iteration of Excel.exe in Task Manager is known as one "instance". Excel has some features that are dependent on the instance it is running inside. You can see it as Excel only being able to communicate fully between files that are running in the same instance. 

To illustrate this, you can try this:

1. Start Excel

2. Click "New workbook"

3. Write something in a cell

4. Press Ctrl+N to open a new workbook

5. Write something in a cell in the new workbook too

6. Press Ctrl+F6 to switch over to the first workbook again

You are now in the first workbook. If you click "Undo" (Ctrl+Z) now, you may expect it to Undo in the workbook you are in. But it does not, it actually jumps to the second workbook and Undos.

Why does it do this? Answer: Because Undo works in a long "list" for all files opened in the same Excel.exe "instance".

Ok, so how do I know what files are opened in the same instance?

-First of all, all files that are opened with "File - New workbook" or "Ctrl+N" should be in the same instance.

-One simple way to test is to press Ctrl+F6. This will jump to the next file that is open in the same instance, if there are any. Any currently open Excel files it does not jump to are in separate instances.

-If you only see one Excel.exe in Task Manager, there can only be one instance running.

Was this changed until Excel 2016?
Separate instances have always acted independent of each other. But starting with Excel 2013, a change was implemented (SDI versus MDI) that improves the ability to work with the same Excel.exe instance across multiple monitors (based on customer requests as more and more customers started using 2 monitors). Read more and see the first 2 pictures of this article. The reason this is mentioned is that because of this change, you might get the impression that there are 2 instances running, while there is actually just 1.

Additionally, a change was made starting with September 2017 updates for Office, resulting in separate instances when opening multiple files simultaneously when no Excel process is already running.

What are the benefits of running multiple instances of Excel?

-If you have 32-bit Excel, each instance can use up to 3 GB memory. If you have a powerful computer, very heavy files, and 32-bit Excel, each instance of Excel can use 3 GB. So with e.g. 2 instances of Excel.exe, you could say that the total memory Excel could use triples. (Please note that this is not needed with 64-bit Excel as it is not limited by 3 GB memory per instance)

-If you want to have a separate Undo chain, so that each Undo only undos in the currently active workbook, then separate instances will indeed achieve this.

What are the negative sides of running multiple instances?

-If you want to have a common Undo chain shared by all open files, then using multiple instances will not achieve this.

-If you want to be able to e.g. press Ctrl+F6 to jump between your open files quickly, then using multiple instances will not achieve this.

-Paste Special will not work between instances. See this for more info.

-Making workbook links between 2 files in separate running instances cannot be made by clicking, and will not update in real-time.

Ok. I have understood the positive and negative sides, and decided that I want to use multiple instances. How can I enforce that?

-You can start Excel with the Start - Run -   Excel.exe /X   command. This will force a new instance.

-Alternatively, you can have Excel running, and hold down the Alt key, and then start Excel again. Excel will ask you if you want to start a new instance, to which you can answer "Yes":

-Alternatively, you can force Excel to always open new instances.

(Please note that the above possibilities will NOT prevent files from opening in the same instance when you press Ctrl+N from inside Excel.)

To summarize:

Each Excel.exe is known as one Excel instance. Some Excel features are shared between all files in the same instance. If you open a separate instance of Excel.exe, then it will not have any "connection" with any other Excel.exe instance, which has some negative/positive effects as outlined above.

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Ok, I get it but I want ALL my files to run SAME instance. Having problems pasting bcoz of this multiple instance ‘thing’ is frustrating and a pain in the ‘you know what!’ So, why does this article OMIT telling us how to ensure ALL files run same instance of Excel? I am really tired of this multiple instance ‘thing’ and believe me you, I am right now doing my utmost best to keep calm and my language polite. Otherwise, I just feel like letting go of a chain of expletives and ‘colourful langauge’ but I realise I will defeat my own purpose, to get an answer and a response. How were multiple instances IMPOSED on me without my knowledge, I wonder?! Please somebody help me reverse this and make sure I run same instances ONLY. Please...


Thanks for the question. Opening files through File - Open should open them in the same instance. As you mention issues copying, I presume that they indeed are in separate instances. Can you let me know more about when you see this problem? Is it when you select multiple files in Windows and open them at the same time, without having Excel already running?

Thank you, thank you, thank you for your response
No. I never select multiple files and open them at the same time. My standard method of operation is as follows:-
1. I open Excel and then create Files via the 'Blank Workbook' template (one file at a time)
2. Having created the Files I save them in My Documents folder (one file at a time)
3. When creating these Files, since it is Excel I also create Formulas within the Worksheets (sometimes I also use conditional formatting)
4. When opening the saved Files I use the following methods
a) Recent 'pinned' Files
b) The Tab 'open Other Workbooks' within Excel
c) By double-clicking on each File where it is located in My Documents (or folders within My Documents)
5. As you can see I NEVER open "multiple files at the same time" as enquired you
The 'different Excel instances' problem starts when I have  opened multiple Files (opened one file at a time) which I am working on. I might want, for instance to use a complex formula I had previously created in another (separate file).  There is no need that I should re-create the same complex formula. I'd rather copy and paste it from one File to another. I have been using Excel since the early 90's. This never used to be a problem. It's only with Office 365 (2013 & 2016) that so-called "instances of Excel" problems started. So, this is a Microsoft created problem. Although it was frustrating, I had no choice but to be patient and SEARCH Microsoft's OFFICIAL Community for answers. Several people have expressed same frustrations but there has never been a satisfactory answer
Hope you ARE our liberater and will provide the right answer as to what are these instances and why are they creating such headaches? We are told how to create these 'instances' but I have never done any of that creating. These 'different instances' are sellf-propagating, why? Excel is SUPPOSED to be a solution, NOT a source of problems in itself
Thank you for taking the time to look into this problem. Your assistance will REALLY be appreciated, a lot (I am sure by many; not just me)
Apologies for the late response
Wisdom Prosperity
+27 82 735 1800
I have earlier provided a reply in a direct message.

Microsoft should not have change the way the workbooks are opened in case there are more than one instance of excel.exe running  ( different pids/processes) .  

Issue description : I was using excel 2010 till now and whenever there were two instances of excel.exe running at same time , if i double click an existing workbook (say mydata.xlsx at desktop )  it use to open in 1st instance of excel.exe , the instance which i launched 1st  but starting office 365 i noticed all my existing workbook opens in the latest instance of excel.exe . 

I'm having the same issue, regardless of whether I open two files at the same time or open one and then File>Open to open the second.  I watch the Task Manager and it opens two instances of Excel.exe each time.
When you say there are 2, are you looking at "Details" tab in Task Manager, or are you looking at "Processes" tab? Because "Processes" tab will list each file on 1 line each. "Details" tab is the one to look at, and there each line of Excel.exe means 1 instance.
This is Windows 7 Pro, I don't have a details tab.  However, under both the Applications tab and the Processes Tab I see two Excel entries.
Does this happen even with new files (files that came from the network may launch in "Protected View"). Does it happen in Word too? Have you set registry keys as per https://support.microsoft.com/en-us/help/3165211/how-to-force-excel-to-open-in-a-new-instance-by-default? Since when is it happening? Have you checkmarked "ignore other applications that use DDE"?
It appears the "Protected View" was getting me.  Thank you.

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Last updated October 26, 2020 Views 14,716 Applies to: