As the spywares are distinctively different from the computer viruses, they are not detected by anti virus software. Therefore, you can not know the existence of spywares in your PC unless you are having a Microsoft anti spyware installed in your PC. It is not that only Windows operating systems are vulnerable to spywares. But as Windows is the most used operating system all over the world, the authors of the spywares find it more effective to create and spread spywares that are compatible with Windows operating systems. So if you are using a Windows operating system, it is always recommended that you regularly scan your PC with anti spyware program to be safe from the ill effects of spywares.
Spywares are mostly used to collect data about the internet usage of the users of an infected computer. Spywares keep track of the website visits, online purchase, file downloads and transfer the data to authors of the spyware who use these data for online advertisement. Apart from this not so harmful threat, spywares can cause much more serious harm to your privacy. There are spywares that are created to steal confidential information like your bank account numbers, credit card numbers and passwords from your PC memory and the browsers. As spywares collect these information by logging the keystrokes when you enter the information at the online forms, you are not safe even if you are using a secured server. Only the spyware removal utility of a Microsoft anti spyware can ensure you optimum online security.
There are so many spyware remover tools available over the internet that you can download for free. In fact, Microsoft itself offers an effective Microsoft anti spyware for free download from their website for Windows users.