PC freezes when using Internet

My PC does fine while using any other application. I can connect to the Internet using the dialup and not have a problem. The moment I execute my browser the PC freezes. I can open MS Outlook without a problem but the moment it checks for email…freeze. My curser doesn’t freeze, everything else on the screen does. I don’t even get the blue screen of death; not even a black screen. Ctrl-alt-delete doesn’t even do anything. I have to hard boot to get things back to normal again. By the way, I’musing Win98. I’ve had this computer for about 1 year and have not seen this problem before until about 1 month ago. I didn’t upgrade Internet Explorer. Please help.