You've hit most of the "traditional" trouble shooting steps.
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As a temp work around, have you tried opening the application alone. The using the File open dialog to open the files. Hopefully that will get you working again.
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Have you tried starting both Excel and Windows (in separate steps) in "Save mode". There may be a bug in an Office / Excel addin or even a 3rd party Windows tool that is causing the problem.
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When you mentioned you didn't want to do registry editing to do a "full" Office uninstall, that is the last resort. MS actually provides a utility you can download and run to do a "full" office uninstall. It is "Method 2" in this tip:
Uninstall Office 365 – 2007
https://support.office.com/en-us/article/uninstall-office-from-a-pc-9dd49b83-264a-477a-8fcc-2fdf5dbf61d8?ui=en-US&rs=en-US&ad=US
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Method 1: Uninstall from Control Panel (or Settings dialog)
Method 2: Completely uninstall Office with the uninstall support tool (SetupProd_OffScrub.exe Which installs S.A.R.A.)
Method 3: Remove manually (Registry Hack)
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The Method 1, “Normal uninstall”, is designed with the assumption that you will be re-installing Office. It does NOT delete everything. It leaves configuration files like NORMAL.DOTM and other templates
etc. It also leaves configuration Registry entries. Normally these “carry-overs” are safe. But if method 1 didn’t fix your problem, they may be the cause.
Note:Method 1 includes links to Office version specific
re-install instructions
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Method 2 (and 3) are intended to completely wipe Office from your computer
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This captures shows a computer with 2 Office installations, 365 and 2016 Pro Plus (that needs activation to work)
Office File Account - 365 activated Pro Plus 2016 not activated.jpg
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Method 2: Downloaded tool (SetupProd_OffScrub.exe Which installs S.A.R.A.)
So if Method 1 doesn’t fix your problem, try Method 2. Method 2 does a more thorough job that the “normal” uninstall (aka Method 1). It deletes “everything” associated with Office
except your personal (document, spreadsheet etc) files created using Office
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* Boot the computer.
* After the restart go to
**http://office.com/myaccount to re-install Office 365**.
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https://www.thewindowsclub.com/ways-to-uninstall-microsoft-office-2007 -
This page lists 7 ways to Uninstall Office. A couple are no longer valid (#3 and #6), but most are.
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NOTE: BEFORE you start the uninstall,
If you have an Office 365 bundle or Office 2016 / 2019, make sure you can access the MyAccount page so you can reinstall.
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