Each day virus, spyware, and adware hackers come up with new, ingenious ways to gain access to your PC. These steps will help keep you safe:

Stop and think before you click: Downloaded files that end with .exe, .com, .bat, and .scr, as well as scriptable document files, including .doc and .xls, can render your computer completely useless with a single click. Most e-mail clients prevent access to any attachments so take an extra few seconds before you make a judgement on whether you trust the source and decide to open it or not.

Make use of a spam filter: Although most spyware and viruses make their way onto your computer via drive-by browser hijacking, spreading by email is still possible. Installing a junk-mail filter will decrease your chances of activating malicious scripts embedded in messages.

Ensure your antivirus applications are up to date: Using antivirus software that has expired past it's subscription period is definitely not an option: Not only do you lack the crucial virus database updates, but you expose your system to malware that targets known flaws in antivirus software.

Prevention against WORMS and Viruses: Install antivirus software, update regularly, and use it regularly. Never open unsolicited e-mail attachments.Disconnect your network or modem cable when you are not using your computer.

Antivirus software is software that is installed on your computer that protects you from viruses. Antivirus software programs can have between 40,000 - 120,000 "malicious software definitions" that receive constant updates.

I highly recommend Grisoft AVG Anti-Virus (Free) for antivirus protection.

If unsure get a 2nd opinion: You should only install and use one single antivirus program at a time on your computer because multiple antivirus programs will conflict with one another and cause your computer to completely grind to a halt. If you have any doubt about your antivirus program's effectiveness, you can use a free online virus scanner, such as Panda Software's ActiveScan) or Trend Micros HouseCall.

Approach downloading with caution: Any program you download and run on your PC could potentially result in spyware or virus infection. Download software only from reputable online sources that preferably have a strict no spyware policy.

Install a bidirectional firewall: Windows XP and Vista each come with a firewall that blocks incoming attacks; it is enabled by default in Windows XP Service Pack 2 and later. However for the best protection possible, you will also want to block unwanted outgoing connections made by spyware, viruses and scripts on your PC that attempts to either connect to a remote server or send out spam.

Windows Vista's firewall does have that fucntionality, but configuring it is not entirely simple enough for the average Windows user. You may be interested to know that, you can get one of several free bidirectional firewall programs, such as Zone Labs ZoneAlarm Free, or Agnitums Outpost Firewall Free.

Install a good antispyware program: Anyone who uses a computer can succumb to spyware infection. In fact, 9 out of 10 Internet-connected PCs are infected with some kind of malicious software. Spyware can be any application that tracks your online or offline PC activity, serves you adverts, redirects your pages and bombards you with pop-ups. If you use the Internet, its very much possible that some form of virus threats are already present on your PC.

Viruses can sometimes go undetected however, it is more likely that you will notice that it is present on your PC due to the obvious symptoms that your computer may experience. It is VERY difficult to get rid of but not entirely impossible.

Even if you think you have successfully removed an unwanted program manually, a remaining dormant file can trigger a complete reinstallation the next time you start your computer. And as a survival tactic, spyware programs often leave similar traces elsewhere on your system so you can often never eliminate it completely on one attempt.

Spyware, adware, and some scripts / trojans slow down your system, cause crashes, and track your online activity. Antispyware utilities work much like antivirus software, detecting and removing the unwanted software from your PC.

One free tactic you can employ is to upgrade from Windows XP: As Microsoft Windows service Pack 2 makes Windows XP much safer, however the operating system still has security holes, and it remains prime target for spyware authors.

If you still have a slow PC after trying the software above and you think it may be due to spyware, you can find more help and information on fixing your slow computer at Slow Computer Help.