Strange Problem with LAN & Wireless Router Connection

Today I was doing up my younger sister’s pc which she brought home from her university hostel recently. I cleaned it & hooked it up to the wireless router by LAN to try to network her pc. It’s supposed to be plug & play when attaching a pc to a wireless router via LAN. Well, it is not so the case for my younger sister’s computer; strange problem. It’s an Intel Celeron with 512mb of ram. The specs should not be an issue. Anyway, it tried everything including calling up the Aztech tech help over the phone. I changed the default connection, checked the LAN connection, put the obtain IP address detection & DNS server address to auto; everything!

It’s not like I am using the wrong cable like in the side picture! The techie informed me that I should reformat the pc & reinstall all the drivers for the pc then try again. Well, maybe another day because my younger sister still has plenty of data in her pc’s hard drive. Heck knows when I will be able to proceed on the task. I hope I get to fix up the situation soon because my father who knows pretty much nothing about computers is using my email account to receive lots of mails from his associate. I hope I get to fix up his own personal email account on my sister’s currently unused pc for his convenience.