system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can't we use \ / : * ? " < > | in windows files names ?

Really, it's bothering me every day.
gpt
Here is a simple example of why you can't use these characters.


This is a valid path to a file:  

    C:\SomeFolder\SomeFile.txt

Now imagine the backslash "\" character was allowed in the file name, and your file was called:

    Some\File.txt

The operating system would now look for:

    C:\SomeFolder\Some\File.txt

It would look at "Some" as a folder, instead of part of the filename, and would have no way of knowing otherwise. 

Certain characters are reserved by the operating system for exactly this reason. Each character has a different purpose in the operating system, but the reason is always the same: to avoid confusion about what the user or program means when it says something.