Excel window all crumbled

Hi, I am going to describe a problem that occurred in one of my Excel files which I have hopefully resolved at least partially, but I would like to understand what happened and how to resolve it in the future.

Beforehand I apologize if sometimes I may not use the correct terms. English is not my mother tongue and my operating system (Win 7) is in Spanish but certainly in the English speaking community, just for the size of it, chances are greater to find people who know this problem.

I have been using an Excel (2007) file for years to trace certain data where I have to add new data nearly every day. The file contains dozens of worksheets and quite a huge amount of data and formulas accumulated in the course of these years. The file was password protected.

About a month ago this file started to behave in a strange manner.
While I have set the system to open any file on a double click, this file would open with a single click, even with the right mouse button. So even when I just wanted to make a copy of the file or see its properties, it would open.
More recently it would even also try to open a copy of itself once I clicked on the file name.

Often the window that opened would appear normal but when I added or changed some data to one of the worksheets, the entire window would suddenly "crumble", i.e. suddenly the rows shown would double in another place of the screen, their format would change, the header (the menu part of the window) would either disappear or only the text part of it would be shown without any graphics and clicking on any part of the screen would just cause en error sound without any other action, no way to continue working. Even parts of the Windows taskbar (like the clock) where suddenly moved to another place on the screen, the file affected everything on the screen. Trying to close the window via the mouse was useless, I had to close Excel with the task manager, killing the process.

Hoping to resolve the problem, I tried to open the file with the "repair" mode, but unfortunately it did not really help. Sometimes I could work with the file and close it in an orderly way and I already hoped that the repair had helped but the next day when I opened the file, the same things happened. Given the huge amount of historic data, I could not throw it away and start from scratch.

I uninstalled my Office 2007 completely and reinstalled it but this did not change anything, although I repeated the process 3 times.

So eventually I found an older version of the file in a backup that I had made some month ago which worked correctly. Then I made another "repair" to my actual file, this time extracting only the data. I also eliminated the password in both files.
Then I transferred the extracted data manually to the old file where they were missing. Now this file appears to work correctly. Clicking on it with a single click will not open it anymore and there does not seem to happen anything strange when I work with it.

To avoid reintroducing this problem again, I deleted all the Excel files that open on a single click and left the file without password protection (which I don't really like).
Basically I hope to have resolved the problem.

What bothers me is that I have no idea what happened.

I thought that the window that opens on the screen when you start Excel is built exclusively by the program itself and that only the data, formulas and graphics shown in the content part of this window are determined by the Excel file. I would expect that in case of a defect Excel file these data may be erroneous, the formulas might not work or the graphics not be shown correctly.
But I do not understand how a defect Excel file can even "crumble" the entire window, destroy its menu bar (what I called "header" above) and even affect parts of the screen that have nothing to do with the Excel window, like the task bar.
And I thought that the behavior of any file on a single or double mouse click would be defined only in the registry, but in this case individual defect files acted different from any other file.

I wonder if anybody else has had a similar problem (or heard of it) and can explain the underlying technical reasons for this behavior.

Thank you very much
"An inquiring mind"

In all honesty, I have no idea. I would suggest that you scan for viruses as that's all I can think of.

I have never experienced the symptoms you are describing but much of it is worrying.

Regards, TMS

Thank you very much for this hint. I ran the diagnostics and it repaired one problem. Unfortunately it is not possible to know what it was and if it was related to my problem.
Anyway since I did the repair that I described (using an older file without apparent defects and adding the data extracted from the defect file), I have not had any difficulties.

Still wondering how a defect .xls file can affect the entire system so heavily.

Some weird and not so wonderful things can happen via a virus, malware, rogue macro in a file that has been opened and failing hardware. The single click is an option under Folder Options in Windows Explorer. Maybe a defect in the file was triggering a change in the setting for this file. I experienced the single click phenomena when a wireless mouse connected to a laptop was starting to fail and unfortunately, it did other things as well like jump all over the place. Disconnecting the mouse returned the computer to normal operation.

I have noticed some strange video and performance problems with files stored on Onedrive with Preview turned on....freezing, partial screen re-drawing etc. Turning off the preview for the file that is open eliminates that. That I think is a speed problem with the network.

Was there by chance a large difference in file size between the file that works and the one that didn't?

It is weird that the effect was on just some Excel files. Uninstalling using the Control Panel can leave behind a bunch of garbage that is incorporated back into a new install. I was having trouble with a driver for a printer and the manufacturer recommended that I uninstall with Revo Uninstaller....it did the trick where the Control Panel uninstall didn't do a good enough job. There are also other programs that do similar jobs of thorough uninstalling.

If this was something that just showed up after the 2nd Tuesday of the month when Microsoft issues its major updates for the month, maybe a Windows update did something unforeseen.

Let's hope that the problem never comes back.

You're welcome.