Spyware is any program that installs itself in a computer system with or without consent to gather information for its programmers. Spying insidiously on unsuspecting computer users, the program watches what users do on computers to send the information over the internet.
It can come with legitimate-looking software to get installed and remain in place even after removal of the software. It can also come with a virus or a worm to get integrated along with them to collect different types of information there are benign and malicious Spyware.

Effects of Spyware – Invading computers to harvest private information, more than 95% of all computers are infected with spyware. Users are at the mercy of these programs that inflict annoying or even malevolent damage causing serious effects. They can,

• Install worms, viruses or Trojan horses to open back doors in computers making them vulnerable to attack by hackers causing identity theft. 
• Alter and destroy important files on your computer including the very heart of your operating system.
• Turn a computer into a zombie commandeered by spammers for the purpose of sending out massive amounts of spam.
• Monitor internet surfing habits to install "keystroke loggers" to record and report on every keystroke including passwords and credit card numbers.
• Change homepages or adding bookmarks not required by users for adware or pop-ups.

Spyware Tips - Everyone battles risks like key trackers, web page redirectors, persistent pop-up advertisements, inoperable network connections, unwanted tracking applications and other nefarious programs that slow and render systems nonoperational. Top three ways to fight these problems are:

• Install a good spyware removal program and keep it updated.
• Be very careful when downloading free programs that frequently loaded with them.
• If you do download always read the User License Agreement giving details of the kind of spyware placed on your computer.

Spyware Adware - is a type of spyware in which advertising banners are displayed while the program is running. Codes in the application delivering the ads appear as pop-up windows or bars on computer screens. They track a user's personal information and pass it on to third parties without the user's authorization or knowledge.

USEFUL LINKS:

Best Free Anti-Spyware: Anti Spyware program safely tackles such threats and keeps your PC risk free and helps protect your confidential documents from being corrupted or hijacked.

Spyware Removal Reviews: Read reviews of the best antivirus software that improve performance of computers by detecting and removing unwanted programs slowing them down.

Yahoo Spyware Toolbar: Yahoo has recently unveiled the feature for its web browser tool bar which is powerful spyware protection to its already existing popular Internet Explorer
Toolbar.

Web Browsing Precautions: Basic defense mechanisms help avoid unnecessary risks and hazards. Apart from getting caught in Internet scams you avoid virus and spam threats.