You might want to open two files in two separate windows to compare them. Also, if you want to edit two files simultaneously, you need to open them separately. That is why you can change Notepad ...

Notepad is the default text editor found in Windows computers. Every .txt file is configured to open directly in Notepad. It has paved the way for text editors over quite some time now, in which ...

Thankfully, you can still re-enable the old version of Notepad by opening the Settings App (press Windows+i) and navigating to Apps > Advanced App Settings > App Execution Aliases ...