Inspiron 15R Wireless Signal Not Strong Enough... Computer or Router Problem?

I use road runner cable internet from time warner. I have a linksys wrt54g wireless router. In our apartment, we have 3 computers. One is a desktop. The other 2 is laptops. One of the laptops we use is in a room very far from my room where the router and desktop computer is located at. The connection for the wireless is pretty bad so you have to go to the living room right next to it to get a better connection.


At first i thought i fixed this problem by upgrading the firmware as i have never did this before ever. I upgraded it to firmware version 4.21.5. At first it seemed like the signal got better from that room but now its as bad as it was before. So you have to go to the other room next to it... living room to use it.


My question is what could be the problem? I put my router on top of my desktop computer so it wouldn't be on the table where so many things could block it. Thus its at the highest point i could put the router in my room.


What wireless network mode am i suppose to put it on? I tried G only because i read thats the fastest but it doesn't seem to change anything. Or should i go for B? Or mixed? We only use the laptops for the wireless internet. We don't have any gaming system or stuff like that.


Also what channel should i have it? I have put it on channel 1 and 6 and it doesn't seem to change. Am i suppose to go through every single channel until i can get a fast connection?


So i tried something different. We have 2 laptops. One laptop is used by someone else all the way in the other room where the signal is pretty bad. Well i then brang my laptop to that room and went on the same site as the other computer and went to load the same streaming videos. My laptop however... the connection was faster than the other laptop in that room which is far away from where the desktop/router is at. Basically you can't even stream a video in that room most of the time but my laptop could.


Does that mean that my router isn't the problem since the wireless signal works fine for my laptop there whereas the inspiron 15r goes much slower? The thing is once you take that laptop and move it to the next room closer... then the signal is pretty good