Fixing a PC that's lost its Edge browser

Q: I began using Microsoft's new Edge Web browser after I upgraded to Windows 10, but now it vanishes from the screen moments after starting. Can I fix this by reinstalling Edge?

Francisco Arriola, Lakeland, Fla.

A: No. If Edge was from another browser maker, you could reinstall it to correct the problem. But Microsoft has made Edge an integral part of Windows 10, so you must instead repair it using some built-in Windows software called "System File Checker." Here's how:

Right click the Windows icon in the lower left corner of your screen. From the menu, select "Command Prompt (Admin)," which gives you "Administrator" authority to make changes to Windows. When prompted, click "yes" to let it run; a black area will appear in the middle of your screen. Type in "sfc /scannow" without using the quotation marks (note that there's a blank space before the slash), then press the "Enter" key. The software will scan Windows for errors, and should fix the Edge browser.

If you get a message that File Checker can't fix the problem, you should run the scan again in the PC's "Safe Mode." To enter Safe Mode, hold down the Shift key while clicking the "Restart" command. (To run the command, left-click the Windows icon, select "Power" and choose "Restart.")

If that still doesn't solve the problem, you can use another built-in Windows fix-it program called "Deployment Image & Servicing Management" (DISM).

Go to the "Command Prompt (Admin)" command again, but this time type "DISM /Online/Cleanup-Image /RestoreHealth" without the quotation marks and press Enter. (Note that there should be one blank space in front of each slash mark). After DISM has run, restart the PC and try the File Checker again. It should work this time. For details, see tinyurl.com/qc5wngf.

Q: I often sign up to receive e-mails from websites such as willowyarns.com. But for months my Comcast e-mail address has been receiving only about half of the e-mails I signed up for. This happens even though I've signed up for some of those e-mails more than 10 times. The problem occurs on my Mac computer, iPhone and iPad, even though I have the latest software updates. What's wrong?

Jean Jacobs, Minnetonka

A: Your devices aren't the problem. You're more likely being affected by the way the Comcast e-mail system works.

If any of the websites sending you e-mail violate the "best practices" of mass e-mailing — such as sending too many identical e-mails at once — they might be blocked by Comcast's mail servers as a way to control the huge volume of e-mail they handle every day.

Find out by creating a new, non-Comcast e-mail address, such as at Google Gmail or Yahoo Mail, then sign up for the website e-mails from the new address. If you receive all requested messages, switch to the new e-mail provider. If you still don't receive everything, split your requests between your two e-mail providers.