A reader is struggling to open attachments in Windows 10:

“I have a very new computer and am running Windows 10. I am now having a lot of difficulty trying to open attachments that friends send me. They used to open automatically and now they don’t. For instance, today there were 2 attachments with one e-mail: one is designated “.htm” and the other is “.mp4 video”. I tried to look up how to open the .htm and got the information that I should look for “view” in Chrome. This led me to “view source” but that led to a long page of incomprehensible text.”

Choosing “View Source” will simply take you all the way back to the origination point of your email. What you need to do is select default programs for opening particular types of files on your computer. Let me show you how.

Start by typing Default apps into your Start box. Click on the results.

default-apps

Scroll down to Choose default apps by type.

default-apps-by-type-pick

At the left is a list of file types in alphabetical order.

type of default-file

The program selected to open the file will appear to the right.

photo-picked

If no program is selected, click on the + icon to choose a default. If you want to change the current default program, click on the icon for the current program. A window offering program options will pop up. Click to choose a program.

choose-an-app

If there’s no program capable of opening that type of file on your computer, you may see a screen inviting you to look for an app in the Windows store.

look-for-app

If apps are available, they’ll pop up in the store.

apps-from-store

One thing I will caution you about, be sure those attachments are legitimate. Scam attachments often appear to have a familiar file extension. But they really aren’t what they claim to be. So if you have a program designated to open .mp4 and it won’t open that file, it could just be your computer protecting you.