Modem/Ports Problem Windows XP

[Dave]

My modem has suddenly stopped working and when trying to
connect to the internet message comes up saying port
unavailable. On running diagnostics for the modem ,
message comes up " The port that the modem is attached to
could not be opened."
The assigned port for the modem is COM3 on checking the
device manager I notice that there are no ports listed and
they seem to have disappeared.

 

[Bud G Seed]

Dave, do you have a firewall or similar that may have "shutdown" this port?

 

[Dave]

Thanks for the response but not sure re the firewall - how
do I find out , and can you suggest a fix?

Cheers,

Dave