What to do when documents, other data aren't downloading properly

Q: My Windows 7 desktop PC can't download Adobe PDF document files from the Internet.

I thought the problem might be malware on my PC, but neither Microsoft Security Essentials nor my newer Avast Free security software could find anything. I wanted to scan with the Malwarebytes security program, so I downloaded it to my laptop, then copied it to the desktop PC via a flash drive, but it wouldn't install there. What should I do?

John Gay, Orange Park, Fla.

A: The Avast Free software may be the cause of your Adobe PDF download problems. Avast is designed to detect malicious software hidden inside PC files, but it sometimes mistakes clean PDF files for infected ones. That might prevent you from downloading those files.

But your PDF download dilemma also might be caused by running the Avast Free and Security Essentials security programs at the same time, because they can interfere with each other. Turn one security program off at a time to see if you can then download a PDF file. Then uninstall the program that seems to trigger the PDF problem.

To temporarily turn off Avast, see tinyurl.com/ool5lef; to do the same for Security Essentials, see tinyurl.com/a3jnawz and click "Go to PCWorld."

If that doesn't solve the problem, try using a different Web browser, because they don't all work the same way. For example, there have been complaints that Microsoft's Internet Explorer 10 and 11 browsers sometimes interfere with PDF downloads (for potential solutions, see tinyurl.com/ncjhuem). Since you already have Internet Explorer, you can download the Google Chrome browser at tinyurl.com/mwd2c3z or Mozilla Firefox at tinyurl.com/7bakrh8.

Q: I haven't been able to view my medical provider's website on my Windows 7 laptop PC, and I keep getting a "324" error message. (I could view the website on my older Windows XP PC.) I've contacted the website's technical staff members, but they can't find a solution. What can I do?

Ron Mrugala, Ham Lake

A: The "324" error means that no data was received by the browser. That could be caused by the website you're trying to load, but it's more likely the result of a Web browser problem (such as accumulating too many cached, or saved, Web pages) or a PC software issue (such as restrictive firewall settings or malicious software activity).

The 324 error seems to occur most often with the Internet Explorer and Chrome browsers. Possible solutions for Internet Explorer can be found at tinyurl.com/pumdh2s. For Chrome, see tinyurl.com/ofttrzr.