How do I protect an older computer against malware?

Q: I have an older ASUS PC running Windows 7, 64-bit, with 4gb of RAM. I was unable to update it to Windows 10 so I am trying to protect it as best as possible with aftermarket apps. Right now I use Bitdefender and Malwarebytes, but also have System Mechanic loaded for general maintenance.

A local computer-repair technician suggested I drop System Mechanic because 1. “it may interfere with, or cause problems for your anti-virus program” and 2. it “slows down the computer.” Do you agree with this assessment? Should I remove System Mechanic? What do you recommend to protect a Windows 7 machine (as best as possible)?

— Barry Brower

A: First, yes, I agree with your technician about System Mechanic. That application includes anti-virus software and it’s not recommended to run two anti-virus programs on the same computer. They can interfere with each other.

By the same reasoning, you’d want to remove either Malwarebytes or Bitdefender.

As for the best way to protect that Windows 7 computer? Since it is no longer receiving security updates from Microsoft, the best way to protect it is disconnect it from the internet. If that’s simply not an option, be aware that your computer is especially vulnerable to hackers and be extra careful about what websites you visit and what links you click on.

Q: I’m struggling with an email problem that I’m hoping that you can help me with. I am getting an increasing frequency of reports from people that they have sent me emails that never arrive at my Inbox. I have several email accounts and addresses that all forward to the Inbox for my primary email address at my personally owned domain. I have had this domain registered with Network Solutions for over 25 years. I use Office 365 for my email client program configured with an IMAP protocol. Network Solutions claims that since this is a private domain, they do not filter the email coming into it.

I have checked the blacklist tool at MXToolbox repeatedly and my domain is not reported as being on any blacklists, although I don’t think that would matter for incoming emails. I do find that if I am having trouble with receiving a specific person’s email sent directly to my personal domain, sometimes they can get through by sending the email to my Gmail account, which then automatically forwards to my personal domain. This sounds to me like a blacklist problem somewhere at the ISP level, but many of the people that have trouble getting messages thru to me are using email domains like @me.com or @gmail.com.

Any idea what the problem is and how to fix it?

— Charlie Buchalter

A: Wow. This is a tough one.

Here’s what I’d look into. First, while you may not have a spam filter (or junk-mail folder) active on your email client, your email-service provider may have a spam filter in play for your account. I know you said you asked and Network Solutions denied they were filtering spam. But their response sounds a little off to me. I’m not sure what Network Solutions means about your domain being “private” and that because of that they don’t do filtering. Question them about that.

Another possibility is that the email addresses of the senders of emails that aren’t reaching you may have been blacklisted as a possible source of spam. That may be a result of spammers having hacked into their account and used it to send spam. In such a case that particular email address may end up on one or more email service providers’ blacklists.

As you note, there are services that help you check to see if your email address has been blacklisted. You may want to ask those correspondents whose messages aren’t reaching you check their addresses.

Finally, the only other explanation I can think of is that your correspondents may be entering your email address incorrectly. My wife has a Dutch name that people are ALWAYS misspelling.