Clean install of win2000 now no modem or sound

Do the devices show up in Device Manager? If so, double click on one to see what it says in device status. If not, are the devices ISA. ISA devices typically have jumpers on them to set resources (IRQ, I/O range, etc.) and you may have to reconfigure them. The reinstall of the OS will mean all devices will have resources reassigned to them. If the devices are ISA, heck even PCI, they may get resources already allocated elsewhere which can cause conflicts and you'll get results like you are seeing.