What is spyware?

Spyware refers to software that's been installed on your computer without your consent and that does things like collect your personal information without you being aware of it, change how your computer or web browser is configured, or bombard you with online advertisements.
Spyware not only violates your privacy, it also creates other problems such as system slowdowns, sudden changes to your computer’s settings, junk programs installed without your permission, etc

Is Spyware a Virus?

Viruses and spyware both fall under the heading of "malicious software," but they're not quite the same thing. In technical terms, a virus is a small piece of computer code – a miniature computer program, in other words – that attempts to spread from one computer to another through email attachments or over the Internet. Viruses range from annoying to destructive in nature: the miniature computer program can do anything from just clogging up your Inbox with unwanted emails all the way to modifying or deleting important files on your hard drive.

Spyware, on the other hand, is only "spread" by someone installing a piece of software that has spyware piggy-backing on top of it, or by browsing to a website that installs it automatically. So the largest difference between spyware and viruses is that, for the most part, spyware does not attempt to spread itself to other computers in the same way that a virus does.

How does Spyware get on my computer?

Spyware and adware automatically installs itself on your computer without you knowing it. This happens mainly when you are browsing the internet, visiting web sites, sharing music, files or photos with others, installing software applications without fully reading the license agreement or when you open spam e-mail.    

How can I know if my computer has spyware?

• If has below phenomenas,maybe your computer has spyware
• You see pop-up advertisements even when you're not on the Web.
• The page your Web browser first opens to (your home page) or your browser search settings have changed without your knowledge.
• You notice a new toolbar in your browser that you didn't want, and find it difficult to get rid of.
• Your computer takes longer than usual to complete certain tasks.
• You experience a sudden rise in computer crashes.

How to remoce spyware

• Update your windows oftenly

Go to http://update.microsoft.com and install the necessary security patches.

•  Install Anti-Spyware to detects and remove spyware

Anti-spyware software is a huge category. In order to remove all the possible infections,I think you should install two freeware products: Microsoft AntiSpyware and Spybot Search & Destroy and some paywares.below is spyware removal software review

Microsoft Windows Defender

Even though the name Microsoft isn't synonymous with computer security, the company's anti-spyware program is an exception. Of course it was written by someone else and acquired. But good for Microsoft for buying it and making the program free. It is excellent. The program is set to automatically scan your computer for spyware and adware daily. It also monitors Internet, system, and application activity for anything unusual, fixing problems as they arise. At the time of this writing, the program was still in Beta 2 testing, but was still very functional. Because most features are automated by default, the average user shouldn't have any problems getting Microsoft AntiSpyware up and running. And my tests show of all the free anti-spyware programs, it catches the most infections,raze  removel spyware .Highly recommended!

Price: Free

Paid upgrade: None

Info: www.microsoft.com/spyware

Spybot - Search & Destroy

Spybot - Search & Destroy is the best spyware removal tool,which  can detect and remove spyware of different kinds from your computer. Spyware is a relatively new kind of threat that common anti-virus applications do not yet cover. If you see new toolbars in your Internet Explorer that you didn't intentionally install, if your browser crashes, or if you browser start page has changed without your knowing, you most probably have spyware. But even if you don't see anything, you may be infected, because more and more spyware is emerging that is silently tracking your surfing behaviour to create a marketing profile of you that will be sold to advertisement companies.It's a raze  removel spyware tool. Spybot-S&D is free, so there's no harm in trying to see if something snooped into your computer, too :)

Price: Free

Paid upgrade: None

Info: www.safer-networking.org

Panda Titanium Antivirus 2006 + Antispyware

Below is the features of Panda Titanium Antivirus 2006 + Antispyware

Keep your PC free from spyware

 Titanium 2006 detects and eliminates spyware and other annoying programs that install themselves on your computer without your permission. Protect your privacy and keep your PC trouble-free!

Blocks hackers and intruders, even through Wi-Fi connections.

Every day, hackers are coming up with new ways of destroying or stealing your information. Titanium 2006 offers improved firewall technology to block intruders, turning your computer into a security fortress.

Titanium 2006 also prevents intruders from entering your computer through Wi-Fi connections. Stop anyone entering your PC without your permission!

Simple to use: install it and forget about viruses and spyware

Designed to provide maximum ease-of-use: automatic, user-friendly, intuitive, with clear reports on the scans performed...

Daily automatic updates

It is automatically updated at least once a day to protect against viruses and other threats.

Spyware X-terminator

 Spyware X-terminator effectively removes Spyware and Adware and can restore your systems performance. Not only will current Spyware on your system be removed, but you will be protected from future Spyware attacks as Spyware X-terminator actively monitors and defends against Spyware and Adware activity as they happen using a comprehensive, sophisticated and constantly updated database of thousands of known Spyware and adware threats. Spyware X-terminator will provide you with constant protection against Spyware, Adware, Dialers, Browser Hijackers, Trojans, Cookies, Key Loggers, Trackware, and other Malware while browsing the internet.

Spyware X-terminator is a Top notch, easy to use, effective Spyware removal tool for you to use to get even the most malicious and devious Spyware and adware off of your computer, effectively restoring your computers performance and help to keep your personal information away from prying eyes.

 Price 29.99

Paid upgrade: yes

Spyware Doctor

Detects, removes and blocks all types of Spyware.
Did you know that numerous programs tested against Spyware Doctor detected only small fraction of Spyware and completely removed an even smaller amount? Also most of them were unable to effectively block Spyware in real time from being installed on users PC in the first place.

Spyware Doctor has the most advanced update feature that continually improves its Spyware fighting capabilities on daily basis. As Spyware gets more complex to avoid detection by AntiSpyware programs Spyware Doctor responds with new technology to stay one step ahead.

 Price 19.95

Paid upgrade: yes

What's the Worst-Case Scenario?

Put quite simply, the worst-case scenario when you're dealing with a spyware infection is that you just plain can't fix it. No matter how many times you run a spyware removal tool, the pop-up ads keep coming back, and the removal tool keeps finding new infections on your computer. Maybe you've even taken it to a local computer shop or to a knowledgeable friend, and they're stumped as well. Once you've reached this point, you're unfortunately left with two choices:

• Live with the way your computer is behaving, as-is,
• Reinstall your computer's operating system.