One problem that often happens with spyware and adware is that they can change your computer’s settings, making it quite annoying for you to even log on. Here, they may change the web browser’s home page. Or, when you search, this page can be changed. Some products even will make other changes to the actual configuration of your computer.
A good anti-virus software will take care even of the adwares. So, always keep your PC safe. I use AVG free but I think a standalone anti-spyware software would be more effective.