While this article applies to all operating systems it deals specifically with Windows as it represents the Operating system used by the majority of our members. For Mac and Linux users not everything may apply but please make sure you take the equivalent measures for your own systems.
There is no 100% guarantee of perfect safety anywhere online, but the following will definitely help.
Operating System: Make sure your operating system is up to date, use Windows update to automatically keep your machine updated. Windows updates are issued to patch known security problems, fix stability issues and update some features of your operating system.
User Permissions: It is not advisable to run your machine under an Administrator account, with both the Mac and Linux additional credentials and temporary elevation of privileges is required to allow any changes to the system, this can be achived in windows by creating a new user account with “basic user” privileges that can be used on a daily basis, this permits normal everyday usage of the machine but helps to prevent unwanted installation of keyloggers and similar malware. This can be done by going to Start – Control Panel – User Accounts, then go to manage another account to create a new user.
Firewalls and Anti-virus. Make sure you have both of these installed and kept up to date. These days to keep this simpler many of the major vendors offer suites of software that will offer anti-virus, a firewall, web browser and email safety features as well as scanning tools for other adware/malware that may be out there. I have listed some of the available packages below, some are paid others are free.
Personally I would recommend buying a good suite rather than relying on a free version. The computer is the tool of your trade so it is a worthwhile investment.
Malware Scanners: It is a good idea to scan at least weekly for additional malware such as adware, spyware browser hijackers, keyloggers, trojans etc. To do this I would suggest either Ad-Aware or Malwarebytes, both of these products offer both a free and paid version.
Wireless networking: Where possible it is best to switch your wireless router settings to a stronger security level, make sure it is set to WPA2 with AES and ensure you have a strong password in place (See choosing a strong password). It is essential to lock down your wireless router to make sure that other people cannot make use of your wireless network or gain access to the machines on your network. Most service providers will do this as part of their setup of your connection, but if you are unsure please contact them. If you have installed your own wireless router please check the documentation on how to make these changes yourself.
File downloads: You will find those that are all too eager to send you links to downloads or offer you pictures through personal messengers such as Skype or Yahoo. Unless you know the person very well I would suggest refusing these offers. All too frequently the link they send you to, or the file you download, will be some form of a virus or a keylogger allowing that individual to capture your account names, passwords, banking information and anything else that may be of value on your machine for their own purposes. Being cautious with what you will accept combined with a good virus/malware product is your best defense against these individuals.