About three years ago, I wrote a short blog entry titled Basic Computer Security. I recently came across this again and realized that much of what I said three years ago has changed. It’s time to update that article for 2009.
Part 1: Scanning and Disinfecting Your Computer
First, you should check to see if your system may already have been compromised. Start by downloading and running the latest Microsoft® Windows® Malicious Software Removal Tool. If you have your system set for Automatic Windows Update or Microsoft Update, you are already receiving and running the latest version as the other security updates are downloaded. The Microsoft Tool removes the currently most prevalent active malicious threats to your system:
The Microsoft Malicious Software Removal Tool differs from an antivirus product in three key ways:
- The tool removes malicious software from an already-infected computer. Antivirus products block malicious software from running on a computer. It is significantly more desirable to block malicious software from running on a computer than to remove it after infection.
- The tool removes only specific prevalent malicious software. Specific prevalent malicious software is a small subset of all the malicious software that exists today.
- The tool focuses on the detection and removal of active malicious software. Active malicious software is malicious software that is currently running on the computer. The tool cannot remove malicious software that is not running. However, an antivirus product can perform this task.
You can also run Trend Micro’s Housecall free online virus scaner (this is a good idea even if you have an AV program but fear it may have been compromised). If the online scanner finds anything and can remove it, great. If it finds something it can’t remove, make a note of whatever virus-trojan-worm is identified and do a search for a removal tool – the best place to start for finding and downloading one of these is probably the Symantec Removal Tools Page.
You should also check for rootkits, using one of these free tools:
Note: If one or more of these procedures has located a malware threat that cannot be removed, you may have to default to a hard drive reformat. If you do not feel comfortable doing this yourself, take it to a reputable computer repair outlet and have them do it for a fee. Otherwise, follow the following steps:
- First and foremost, back up all your important data files because a hard drive format will erase everything.
- Make sure you have the original installation CDs (or backup copies of those setup disks) and the Product Keys for your Windows XP or Vista operating system, your essential software (e.g., Microsoft Office, your banking software, etc.), your antivirus software, any other security software and system utilities, and the System Drivers CD for your specific computer manufacturer. All of these will need to be reinstalled following the reformat, along with your data files.
- For more detailed instructions on how to proceed, see How to partition and format a hard disk by using Windows XP Setup or How to install Windows Vista. Additional detailed instructions and suggestions are available at So you are going to reformat and re-install Windows.
See also:
 Spyware Doctor AV |
 PCTools Internet Security |
