Losing internet cable connection

For a little over a month,I`ve been losing my highspeed internet cable connection when I start the pc up the next day.

I have to unplug the cable modem,wait a minute,plug it back in and reboot the pc.Then it works again.

A serviceman from the cable company installed a new cable modem and checked the wires outside which didn`t fix the problem.
He said it sounds like my IP address keeps getting dropped.

I called the company back yesterday and they said to connect the modem to the USB port,(instead of ethernet) to see if it still loses the connection.
I did this and the connection was again lost today.

I will be calling them back,but does anyone know why this is happening and the likely cause of the problem?It`s really pissing me off.

There is no router,just a cable modem.I have Windows XP Home.

There is another guy in my building with the same cable company and he says he has no problems with his connection.

 

Do you start the modem and the computer at the same time?

You should start he Modem first and wait a minute until the modem is Loged On and then start the computer.

 

The modem is always plugged in and turned on,even when the pc is off or on standby or hibernate.
There is no on/off switch for the modem.