Having different OS is not a big deal. It can't affect the network. Infact I am also using different version of OS in my PC but I don't have any problem in my network. But if that would be your technician's last alternative then try to reformat it.

I am already starting to make back ups in my important datas. Maybe by weekend, he will reformat my pc.

Just confused, what is correct? must the two pc have the same ip address to be given? or what?

No, we can not have 2 or more same ip address in same network. May I know what is the ping result? Do you have any firewall installed? Do you have any router install on your network? Please briefly discribe your network setup. For example, 2 windows pc connected to switch, adsl modem connected to switch etc?

Have you tried pinging your IP on the command prompt? I agree with helmishariff, that we cannot have an identical/same IP address in one network. If that happened, I'm sure that would be the cause of your problem.

Actually we have different IP address for both computers. I was only confused. Thank you guys for giving attention for my questions.

At last my problem is now solved. There was a system installation error in my pc that is why we were not able to come up the networking well. Although we have already set up the home networking rightly.

Anyway, I am now contented and happy that both pc can access to each other.

How did you fix the problem? It may help others who are having the same problem.

Mini

We let the technician repair this problem. He do Format C for both computers and install the operating system again. At this time, we have the same operating system (windows XP Prof edition) and at the same time, he made the networking installation.

Glad to hear that your problem been solved already.