When does your computer get infected?
Many free software programs have various degrees of spyware that installs itself onto your computer. Also, while surfing the Internet, some pages can install tracking cookies without you knowing.
If you like downloading free software from places like download.com and zNet, it would be a good idea to read some of the negative feedback about the software program you are interested in.
Click here to read some user opinions about a very popular free program called Kazza.
Some scumware will remain inside your computer even after you uninstall the original program which installed it in the first place.
Example: I was at a friends place removing a program which installed some scumware onto his system. I removed the original program then deleted the adware. What happened is the spyware re-installed itself into another directory. This is a nightmare! I suggested that in the future, he should take care before clicking a yes button on a pop-up window.
Note: I still use the Alexa Toolbar regardless.
How To Remove Spyware, Adware and Scumware
Recently, I downloaded and installed a good Free program called Ad-Aware.
Ad-Aware scans your entire computer, identifies known spyware and removes it. You can also view the Object Details and see what type of adware it is and it's classified risk level.