A spyware program is generally not as harmful to your PC as a virus or worm. It’s mostly innocuous like popping up unwanted ads or solicitations on your browser, or having a new set of unneeded toolbars or a pornographic website for your homepage that you can’t change. It does work on the background most of the time gathering personal information you are not aware of.

But there are instances when it does render the PC nearly useless. Rarely does a single spyware have any noticeable adverse effect on the PC performance. The problem lies in the fact that spyware alters the Windows registry, often working together with other spyware components and programs that have accumulated over time. Multiple infections can increase CPU utilization, eat up memory and hard disk space and effectively render even the simplest task painfully slow. System crashes and stability problems have been known to happen as a result.

Most of the time, spyware activity goes in the background that the typical user is not aware of. And users won’t even know that their PC is infected. They wrongly attribute PC performance degradation to Windows OS or hardware issues and promptly contact technical and after-sales support offices. A clean re-installation of the Windows systems is commonly advised and always neatly solves the problem. But only until they start browsing again and a new set of spyware gets installed.

Some spyware are known to hijack legitimate applications that exploit their vulnerabilities. Windows security programs, firewalls and browser security settings have been known to be compromised by spyware, making them even more open to spyware or even virus infestation. Some disable anti-spyware or anti-virus programs as well and even other spyware programs that might compete for their revenue potential.

There are a breed of spyware that are difficult to remove manually because they alter system file and multiple registry configuration settings. Correcting or restoring some of these configuration settings can adversely affect operation of some networking and application functions as well. And in most cases, only a good proven Anti-spyware utility program can do the job of completely neutralizing spyware.