File Extension Help (PC)

Catcher Block

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Mar 7, 2006
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St. Louis
When I save files at work, I use a pretty standard naming convention, such as April 24 Buyer List 4.24.21 for a list of people who bought an April 24 date as of 4.24.21.

At some point in the last month or so, Excel has taken it upon itself to brand any files that I've saved ending in ".21" as Excel files with the type of 21 File. Best I can tell, this isn't actually a file type. This happens for text files, spreadsheets, and image files--anything I save with the .21 at the end of the file name. (Screenshot below. The middle file was originally a JPG but changed formats when I saved it.)

This is firmly in the annoying-not-fatal category, and I can get by saving files with the date in parentheses if I have to, but I've been using this naming convention for 15+ years, and I have to imagine this is fixable. (Probably something I created by trying to force Excel to open a file ending in .21 at some point by accident.)

Googling for a solution has failed me on this, so I'm hoping someone here might be able to point me in the right direction. I'm on a PC running Windows 10 Enterprise and Office 2016. Thanks in advance for any thoughts on this.


File Extension Issue.PNG
 

LoweTek

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May 30, 2005
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Use dashes instead of dots in your naming if you're going to have a date reference in the file name.
 

SumnerH

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Jul 18, 2005
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Turn off hiding of file extensions and make sure they end in .xlsx

The full name is supposed to be "April 24 Buyer List 4.24.21.xlsx", but the combination of hiding file extensions but overriding them if you have a period in the filename is probably what's biting you.
 

Bergs

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Jul 22, 2005
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Use dashes instead of dots in your naming if you're going to have a date reference in the file name.
This is best practice, but it won't change the fact Excel is now associated with ".21" files.

Turn off hiding of file extensions and make sure they end in .xlsx

The full name is supposed to be "April 24 Buyer List 4.24.21.xlsx", but the combination of hiding file extensions but overriding them if you have a period in the filename is probably what's biting you.
This is correct.


... (Probably something I created by trying to force Excel to open a file ending in .21 at some point by accident.)...
Yep. To get rid of the ".21" association, check out the below:
https://techcult.com/how-to-remove-file-type-associations-in-windows-10/
 

tonyandpals

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Mar 18, 2004
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If you're going to go down the path of changing your naming convention, lead with format like 20210421. Comes in handy as it's sortable.
 

cardiacs

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Jul 15, 2005
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Milford, CT
Turn off hiding of file extensions and make sure they end in .xlsx

The full name is supposed to be "April 24 Buyer List 4.24.21.xlsx", but the combination of hiding file extensions but overriding them if you have a period in the filename is probably what's biting you.
This is the answer.
 

djbayko

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Jul 18, 2005
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