Hi I live in Australia

Question

Hi I live in Australia and have brought D-link dir-300 Wireless G router 1st off I have on screen D-link Quick router setupQuick router set has discovered that you are already connected to a router (Would this be my tall tower that I have my desk computer attached to) Many people choose to replace an existing router with their new D-Link router. (up till now I didn't know I was connected to a router once again I'm thinking it is the tower as referred to in 1st set of ()?) It then askes are you replacing an existing router? (.) Yes ( ) No click next to continue. When I click to continue I'm not sure if I should be disconnecting my power and cables off my tower as then I wouldn't have any means of seeing my desk computer screen or I should think operating my desk computer or even continuing with installation Am I correct in this thinking?