What error message do you get if you don't unplug the USB modem? If your USB modem doesn't initialise it could be a faulty USB socket: do you have any other USB devices? (printer, mouse, keyboard, scanner) and do you have a similar problem with these? There also may be a program starting on bootup that is upsetting your modem: run msconfig.exe and on startup untick everything except the registry scan and systemtray. Reboot with the USB modem plugged in and see what happens. Scandisk is notoriously bad in Windows 98 as it will reset if anything writes to the hard disk. The 1st 10% is always quick but then it will eventually fail. You can get rid of any background applications (which write to the disk) by pressing Alt + Ctrl + Del and stopping everything except systray and explorer before running scandisk but it is best to run it, and defrag, in safe mode (hit F5 or F8 during Windows bootup).