Modem/Callback problem in Windows XP

Hello.
I have a modem Origo FM-56PCI-HSF (with Conexant chipset) at
home. At work I have wireless internet and my idea is to connect
from home to the pc at work and use internet. And plus since
the modem at work is free, I would like to use callback. I
had this done in Windows Millennium Edition, but my problem with
it is that it freezes down at various circumstances (like trying
to update windows with WindowUpdate, clicking ctrl-tab while
connected etc). Because of this I wanted to set up the connection
in Windows XP (that works flawlessly). Now, I`ve set up a connection,
i`ve typed in the number, ip adress, DNS server but when I try
to connect, I experience an error. I can make the connection with
no problem (even the callback) and Windows popups with a message
that I`m connected, BUT I CANNOT use the internet. I can only
connect to the pc at work by FTP or whatever, but I cannot browse
the internet. I dunno what option did I forget to turn on... Maybe
some stupid option

Question 2:
When doing callback, the modem is set up to bring up the call after
2 rings. This is annoying sometimes because we have 3 telephones at
home and it`s not good when I hear 3 telephone ringing at once.
This needs to be done in Hyperterminal I suppose by changing the s00=0
or s00=1, but I dunno how. Althrought I set it to "1", it saves it under
2....

Question 3:
Any idea why does my Windows Millennium freeze under strange circumstances ?

My PC configuration:

Abit KXT333 (VIA KT333 chipset)
Athlon XP 1600+
Origo FM-56PCI-HSF (installed at home and at pc at work)
Windows XP with SP1 (installed at home) + Windows Millennium
Windows XP (installed at pc at work)

ANY help is appreciated. The worst is that I don`t know why cannot I browse
(use) the internet when I`m connected to the remote pc. I can overcome the
ringing problem or the WinME problem if it would work in Windows XP

Thank you for your patience,
Ice-tk4