Some quick computer advice:

This happened to my husband's computer, and he has no clue how it got infected -- it can be as innocuous as clicking on a link in an e-mail purportedly sent from someone you know or some organization you trust.

These "Personal Security Center" popups will try to sell you an anti-virus program. DON'T FALL FOR IT -- it's a scam. (If you already paid, call your credit card company and dispute the charges.)

Once you see these pop-ups, which are designed to resemble real Windows security alerts, you need to take quick action. You need an anti-virus program (good free ones are available from AVG and Avast); in addition, some ISPs offer anti-virus protection as part of their service (ours has McAfee). More important, though, is getting Anti-Malware from Malwarebytes.org. -- also free. (Paid versions of all these, with additional features, are available, but the free ones worked for us.)

Because this malware can block real anti-virus/anti-malware programs from running, we downloaded the anti-virus and anti-malware programs to a thumb drive on my uninfected computer. We ensured that his computer was disconnected from the Internet and started it in Safe Mode. Then we moved the thumb drive to his computer and ran the anti-virus and anti-malware programs from the thumb drive, but had them scan his C drive. You may have to run both the anti-virus and anti-malware programs several times; it took at least a couple of hours to ensure that the computer was clean.

When the malware is gone, install the anti-virus and anti-malware programs onto the formerly infected computer and run them regularly.

We now return you to the Radiation Recall discussion.