i had a 8 port (Ethernet) router, 2tb usb external hdd, and 5 desktops,1 laptop (wifi embedded) and a epson printer.

i need to use that 2tb usb external hdd as centralized storage and as well as epson printer too.

First of all i get internet from dsl modem which has 4 ethernet ports and also wifi in it.

A wired connection from dsl moderm to router.Then i connect Ethernet wires to each pc's from router. Printer is connected to first pc.

note: my dsl modem doesn't support inter-connective so i used a all-in-one-router.

You need to connect the external drive to the a desktop pc or laptop, then create a share to the external drive and give everyone read/write access, then other users can access to it via the \computername\sharename.

thank you. Mr.peter.j.hutchison . But what happend that particular PC/laptop is switched off. still i need the hdd from the other pc. is it still share the hdd for data manipulation.

No you will lose connection to it as the laptop is providing the service. If you want genuine network access independant of PCs or laptops, then you need a NAS (Network Attached Storage) device , which is basically an external HD with an Ethernet port and built in NAS services.

If you want to reconnect, you cannot connect to another PC, set up a share on that PC, and connect via \newpcname\sharename.