So, instead of calling for the 24hr hotline for the router (the last time I called, couldn't understand a word they were saying), I decided to use the trial and error method to fix the problem.
Started off customising the MAC filter on the router admin page @ http://192.168.0.1/ to include the laptop in the list of allowed computers. Realised that the new laptop wasn't in the DHCP clients list (Dun ask me what that is... up till now, I don't know a thing about what I just said). After meddling around for like 1/2 an hour, I finally got the laptop in, and added the physical address to the MAC filter list (go start, run, type "cmd", type "ipconfig /all", and you'd see the physical address). That being done, I go back on to the wireless connection list and guess what? Yaay! The network is still not there.
So I guess maybe the network needs to be added, before it can be seen. Under network connections, I added a new network, and keyed in my WEP password which was configured earlier. The network was added successfully. And guess what? Yaay! Still cannot see the network.
So I decided that maybe I need to manually connect the laptop to the router by using a LAN cable and then configure the MAC filter options from the admin page. Worse, nothing happened, but I have a whole lot of cables connected everywhere, and I have to get them all out.
After like 2 hrs of meddling with the laptop... I finally gave up.
Just as I was shutting down the pc, an ephipany hit me. I walked over to the modem and router, off the power switch, switch the power switch back on and guess what? My network appeared!!