I had Windows ME on C drive and Windows 98 on D drive. I could boot from C or D drive. I installed Firewall and ntivirus programs on both operation systems. Strange things happened: 1) Recently I had to boot my computer with start up disk; every time I wanted to use it. 2) Last time I used Internet on C drive with Windows ME. I could listen to radio through Real Player. But I could not open almost all web page. 3) Next day, I was unable to use Windows ME on C drive at all. I switched to D drive. But I could not boot there either. 4) Laster, I found that my C drive became unformatted. Where is my data? 5) Laster, I found that on D drive, my Wndows98 there, most of the folders and files under Windows folder are gone. Instead, there are many strange folder's name, like that with capital letter, ADCXMRW3, EXCZW3EH, GCOGW1PF... and so on. I do not understand what is wrong. It looks like my computer was infected with virus. But I already installed Norton Antivirus2002 and ZoneAlarm on my computer. Thank you for your help!