HP Compaq Presario,Presario 1800-XL1 User Manual page 125

Symptom Problem
If no dial tone is
found, another
telephone handset on
the same line is not
on the receiver.
Messages are
not cleared from
answering service.
Instant Internet ISP connection is
Zone buttons do not established.
not respond.
Internet
Solution
Verify all telephone handsets
on the same line are on the
receiver.
If you use an answering
service that modifies your
telephone's dial tone to inform
you of messages, clear all
messages and try your
call again.
Connect to your ISP and
retry the Instant Internet
Zone buttons.