XP Home Network

We have had three computers on a network for over a year.
Verizon DSL "Wirespeed" modem, D-Link DSS5+ router.
Four days ago the two remote computers, both Emachines PCs lost their
connection to the network. (No internet connection)
Brought one PC down and connected it direct with a new cable to the router,
direct to the modem etc. still no connection. Went through all of the
reboots, power up and down devices etc.
The "Local Area connection Status" messgae says- You might not be able to
access the internet or some network resourses. The problem occured because
the network did not assign a network address to the computer.
Any suggestions?