Last week, I tweeted about repeatedly seeing a mysterious and suspicious pop-up command line window on my desktop PC. As it turns out, this is a widespread issue. So here’s the fix.

First up, the good news: This isn’t malicious behavior or any kind of malware. As it turns out, it’s caused by Microsoft Office.

OK, here’s what’s happening.

Last week, I tweeted about some mysterious behavior I was seeing on my main desktop PC only.

I keep seeing a command line window pop-up and then disappear in a second. 10-15 times a day. I am sure this is normal & nothing is wrong.

(That last bit was sarcasm, by the way. I was actually concerned by this behavior.)

I received a number of helpful responses, including one from Dave Dustin, who forwarded me to a Microsoft Answers post.

After noting that I would test the fix suggested by that post, I followed the instructions there, which amount to changing the account under which two background processes related to Microsoft Office run from “User” to “System.” When you do so, the processes will not display a UI, so the pop-up window is eliminated.

I can confirm that this fix works. So if you’re bedeviled by these pop-ups, you can get rid of them now. Or you can wait for Microsoft to issue a fix: This issue was a mistake that it is aware of, and I’m told it will be fixed soon.