What do you call the little thingies to the left of the filename?

[raccoon]

And how do you say it when the computer doesn’t know what kind of files the files are, as in the PDF files that appear with a white rectangle on the left?

[NYC_SKP]

1. Those are filetype icons. I don't know why your computer doesn't know how to attribute an icon.

I would right click to look at attributes but I don't use PCs much, not sure that would help.

[CurtEastPoint]

2. right click that pdf file and go to Properties and click Change

tell it what program to use to open that file type and when you find adobe (pro or reader) select it and the plain white icon you see now will change to the red PDF icon.

[PoliticAverse]

3. The file extension association...

(the program that is associated with that file type).

It appears your computer doesn't know what program should deal with .pdf files.

For an explanatory video see:

Do you have a favorite program you like to view .pdf files with?

[raccoon]

4. Thanks, everyone! I use Adobe Acrobat reader. nt