Problems with retaining preference settings

I am a Linux novice but have been very happy with my A110 running Linpus Lite until Iast weekend. I lost the bottom right toolbar and had to log out of the internet connection by turning off the main power switch. When I logged back in a welcome to firefox window opened along with i google homepage and the google toolbar. I have got rid of the toolbar but cannot stop the other 2 windows opening each time I boot up. I have tried to reset the homepage but this preference is not retained after shutdown and I note that other preferences are being reset each time such as the check box for remembering passwords and clearing private data etc. I am used to a Windows environment and would think that this was indicative of a virus. I am so new to Linux that I don't know how to check what is going on. Is it possible that my machine has been hijacked? I thought I would use the recovery disk to make a USB recovery stick and restore to factory settings but cannot get the DVD to go beyond the first step before it hangs at the progress bar. All in all I would like some advice please!