Hello. I have had this question on my mind for months now. It seems easier to use windows file explorer to delete assets that aren’t wanted or used than using the content browser inside UE4. Are there any risks deleting files from windows explorer? Are there any risks deleting files inside the content browser? Please explain.
VERY DEFINITELY do it in Unreal 
Windows will let you randomly delete files, but doesn’t understand the relationship between them. If you do things in windows, your project will be unusable, and you’ll need to start again.
Find out about the reference viewer:
You will find there are all sorts of connections you hadn’t though of…
Sweet, Thank you very much for the information! Its a good thing I decided to ask before destroying the project I’ve been working on for about 4 months now.