Today’s tip is not going to be very long and elaborate. It’s a pretty common problem with a simple fix (most of the time). But if you don’t know the solution, it can be very frustrating because it seems like something major is wrong with your computer.

Here’s what usually happens:

You try to go to a website and instead of the website content, you see a big warning on your screen. The warning is telling you that you should not try to access that website, because the website’s security certificate has expired. The warning would look something like this:

That might look pretty scary – like the website has been hacked and taken over by the bad guys or something. Or maybe the owner of the website forgot to renew the site’s security certificate, which means it is no longer secure to use. Or what if the site has been infected by a virus, and is infecting any computers that visit that website?

The most likely explanation is that it’s none of those things. The problem isn’t with the website – the problem is with your computer. But it’s easy to fix.

Look down in the lower right corner, where the date and time are displayed. I’ll bet you’ll see the date and time are incorrect.

In fact, the date might be off by a decade or more. What happens is this: inside your computer is a small battery, about the size of a nickel. It’s called the CMOS battery. That battery is what enables the computer to remember the date and time and some other things, even when the computer is turned off and unplugged from the wall. Many times, that little internal battery will last the computer’s whole lifetime without needing to be replaced. But in some cases, that battery wears out. You wouldn’t really notice this as a problem as long as the computer is plugged in. But when you unplug the computer, and the battery cannot hold the date and time any more, the system reverts back to a way-earlier date and time. You might not even notice that the date and time are wrong, since you probably don’t look at it very often.

But when you try to access a secure website, that’s when the fun begins! Your browser automatically compares the date of the website certificate with the date and time on your computer (since it assumes your computer’s date and time are correct). When it sees that the computer says that we are in the year 2005, and the site’s certificate was created in the year 2013, that sets off the alarm bells.

To the web browser, it appears that something very suspicious is going on – so it throws up the warning to tell you it’s probably not safe to access that website.

As I mentioned, the solution to this issue is a simple one. Just correct the date and time on your computer. To do that, right-click on the actual date and time that is currently being displayed and in the menu that pops up choose “Adjust date/time”. That opens a new window – just click on the “Change date and time” button and click OK a couple of times so that the proper date and time are displayed.

Now close your web browser and open it again, and see if you can access that same website. If so, problem solved – temporarily. You may need to have that internal battery replaced. It’s a small job and the batteries aren’t that expensive so for most computers it’s no big deal. For some laptops and a few all-in-one desktops, those batteries are a real pain to access, so it might be more of a project.

If the computer is showing the proper date and time and you STILL cannot access the website, trying checking a few other sites like Facebook or Google. If the problem is only with one site, then that’s something the website owner needs to address. If you still get that same warning on those other sites, there is probably still some issue with your computer that needs to be diagnosed and fixed.

But in most cases, changing the date and time will take care of it.