You should never have to reformat a drive for a relatively easy problem to solve. You first take a look in the device manager under network devices and try re-entering your ISP assigned user name and password. If a driver was knocked out you simply right click on the device with a yellow mark on it and browse the driver folder on the cd or folder where you keep them to have Windows reinstall them. Sometimes when seeing a yellow mark on a device listing Windows will search for and install an updated driver set. Or a reinstall of the software and using the IE connection wizard are options to consider.