From: Computerpilot on 12/04/2002
'Jo S' is right. It is a hardware issue. Whenever your computer just completely locks up or restarts itself, it is defective hardware or too many hardware devices sharing an IRQ. These are the two issue that I would suggest you investigate. Actually, Windows 98 will exhibit the 'freeze' during a hardware problem where Windows XP will tend to 'restart' when it encounters a hardware conflict.
Take a look into your IRQ's (can be found in 'System Information'). If you have too many devices on one IRQ, then you probably need to change IRQ's for one or two of the devices. The easiest way to do this is to move devices in PCI slots to other PCI slots. Otherwise, some devices will allow a change in the Device Manager.
I would look into your cable modem. I bet it is USB. These types of cable modems are nothing but trouble. I usually recommend that users consider a network card and crossover cable. The USB cable modem draws quite a bit of power as well from your computer. Look at this item in the IRQ's to find if it is sharing with another device. If you find another device is sharing an IRQ with this and are successul in changing that IRQ, you will probably fix your problem. Either that, or get yourself a cable modem with NIC interface rather than USB.
Good luck and feel free to post back.