This month we're going to look at the first steps to take when you think your computer may have a virus. Sometimes you'll notice that your computer is producing lots of pop-ups. Or perhaps you find your searches are no longer going to google.com, but somewhere else. Perhaps you've noticed that bookmarks that used to work don't work any longer. Or perhaps you're seeing toolbars at the top of your browser that you don't remember installing. It's time to take action.
The first thing you should know is it's probably not a virus. Virus infections are becoming relatively uncommon. Most likely you've encountered spyware or adware, or perhaps a Trojan horse. These, plus viruses, are all categorized as malware. That's a more general term that means software that intentionally does something bad to or with your computer.
These days the most common malware people encounter are Trojan horses and adware. The unfortunate part of this is that it's almost always installed by the user. Usually malware of this type is installed when the user is installing some other software, and the malware comes along for the ride. Typically these will be things like toolbars that hijack your browsing, that are installed when you agree to install anti-malware software. Often after seeing a pop-up on your screen complaining that your computer has malware and you need to fix it now!
The first thing to do is run your anti-virus program. If you're on any Windows computer below Windows 8, Microsoft Security Essentials (MSE) is a good and free anti-virus program. If you're not running an anti-virus program get and install it. If you are, don't install another. Two anti-virus programs at once is a recipe for a slow computer. If you're on Windows 8+ then Windows Defender is already installed and serves the same purpose as WSE. Just make sure that it is turned on. This can be checked in the Action Center.
The next thing to do is run an anti-malware program. I like Malwarebytes Anti-Malware (MBAM). It's available from malwarebytes.org. Make sure when you install it that you un-check the “Free Trial of Professional Version” in order to run the free version. Once installed it will update its malware database. Then scan your computer. Take whatever actions it recommends, usually Quarantine, at the end.
Now you need to clean up all the detritus that has been left behind. This is where CCleaner comes in handy. You can download it from piriform.com. This is a good program, but some versions want to install Google Toolbar and set your home page, which is an annoyance. Un-check these, if offered, before installing. Once installed you'll want to choose Cleaner from the menu on the left and then Run Cleaner. Don't be surprised if this finds several gigabytes of trash to remove. Next you'll want to clean up the registry. Choose the Registry from the menu on the left. Now choose Scan for Issues. Then choose Fix Selected Issues. This will display a pop-up menu asking if you'd like to save changes. Say yes. I've never needed it, but this file can restore any changes that CCleaner made to your registry if there's a problem.
Finally, you'll want to remove any extensions that have been installed in your browser. This is browser dependent so this is best searched for. Try “Manage Add-Ons for Internet Explorer” or “Chrome remove extensions” to see step by step instructions.
If you want to try it yourself, in Chrome it's easy. Just click the settings menu on the top left. Click Tools then Extensions. Now click the garbage can next to any extension you don't want.
In Internet Explorer click the Tools button and then Manage Add-Ons. Delete any that you're not sure of.
Now reboot and check if everything is working correctly. If you're still having problems now is the time to call the local computer repair technician.
Finally, don't wait until you have a problem. Make sure the tools I've mentioned are installed and working correctly now. Also, please, if you do nothing else, backup your data. Worst case you can wipe the drive and reinstall Windows and restore your data. Contrary to what you might think from watching CSI, it's not easy to bring back precious photos and data once they're deleted.