Hi Somaye
Here in the forum, members try to help others and get help also from others
One way of trying to get help is to do your best and then ask doubts, as I said did you check the settings of the firewall, is there any connectivity, can you do ping alfresco server
If you try all this and then post,it will be easy for us to help you.
At this stage check the basic network connectivity of the PC, as you had mentioned that from other PC accessing alfresco is possible
Thanks
Joseph John