I agree with taxidual, if it can't continue it is usually because the updater can't find appropriate drivers. You'd need to have the driver install disk for the motherboard in the drive for the update to work.
Why this has suddenly started happening might be more of an issue. Devices generally don't just stop working and require the drivers reinstalled for no reason.
Either there is a fault with the USB chipset on the motherboard, or some form of corruption has crept in. I would place money that it has been quite some considerable time since the OS was freshly installed. The registry is perhaps, too big, very fragmented and becoming more prone to errors and problems.