Windows 10: File Explorer looks weird

What has happened to File Explorer? Why does it look weird and how do I return the old version?

:)

 

File Explorer Looks Weird

When I go to File Explorer on my Windows 10 laptop, it looks weird. Any highlighted files won't appear as highlighted, the scroll bars are just black and hovering the mouse cursor over options in the right-click window get bolder. I would show you a screenshot
I took, but the "Choose File" button on this website doesn't even do anything! Please help!

 

File Explorer - Dark theme looks weird

When I change my "Default App Mode" in personalisation settings, File Explorer doesn't look like it should:



I seem to remember having a program at one point that changed how file explorer looked (Classic Shell) but I've uninstalled it. I've looked through my list of programs and nothing jumps out at me as something that might be editing the look of File Explorer.

Interestingly, dark theme File Explorer looks fine for a new user on the same computer.

Any ideas on how to fix this?

 

"This file can't be previewed" problem in explorer

Hi Deborah,

For us to provide an accurate resolution, kindly elaborate the issue by answering the questions listed below:

• Since when have you been experiencing this issue?
• Were there any changes on your PC before this happened like software or updates installed?

For initial troubleshooting, we suggest that you follow the steps listed below:

• Open File Explorer.
• Access this link
  
  C:\Users\USERNAME\AppData\Local\Microsoft\Windows\Explorer
• Delete all the files.
• After deleting the files kindly try and see if there's a thumbnail preview of your files.

We're looking forward to your response.