Dial-up to access the internet

Hi,
I have a computer that dial-up is used to connect internet though rarely use it to browse websites. I still use this computer from time to time because some programs are running on it.
However, recently an error message namely AC-1103 0x84200106 is appeared when I try to access the internet. I have no idea what the problem is.
The computer is running on Windows XP with an 11-year old gateway and SP2 and SP3 are not downloaded.
I appreciate that someone could help. Thanks in advance.
