5 whys problem solve!Whys my internet so rubbish! (IP CONFLICT) It should be good with 20MB! I have a fast router as well! HELP?!?!?

Ok i got new internet with Virgin. 20MB Fibre Optic Broadband last week. I have 1 computer, 1 laptop, a ps3 and xbox 360 in my house which are all actively used of a NETGEAR N150 ROUTER (i think) PROVIDED BY VIRIGIN. But theres problems... and there should'nt be with 20MB Fibre Optics...I'm paying enough a month!

Theres a pic below on link, it looks pretty much like this:-
http://www.google.co.uk/imgres?imgurl=https://www.virginmedia.com/images/hub.png&imgrefurl=http://help.virginmedia.com/system/web/custom/viewArticle.jsp%3Fuuid%3D0D2C8879-A99F-4250-A24F-9E2F1C90339B&usg=__6_Vn5XL6haN9bpVYiirqlki7uJc=&h=339&w=180&sz=22&hl=en&start=0&zoom=1&tbnid=RXt0VEjTN_JPDM:&tbnh=111&tbnw=62&prev=/images%3Fq%3Dnetgear%2Bvmdg280%2Brouter%26hl%3Den%26biw%3D1276%26bih%3D599%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=rc&dur=141&oei=EgwNTZahA86xhQej5eG3Dg&page=1&ndsp=21&ved=1t:429,r:5,s:0&tx=26&ty=28

So basically...

My orignal computer which is mainly used dosent work! It worked the first time when the Virgin guy set it up, i turned it off one time and back on and it didnt work! It keeps saying 'IP CONFLICT'' which5 whys problem solve i'm working on but you guys can help :) I dont no why it keeps saying that! Any advice???

Also...

My laptop cant be less than 3-4 feet away from the router other wise it just says connection 'VERY LOW' and it shouldnt. My xbox is connected via ethernet but as soon as i take it in to my other room to play wirless which is about 6-8 metres away, it dosent even have any bars of connection! I even tried the xbox guide on their website, didnt really help.

I thought 20MB Fibre Optic BroadBand with Virgin should pretty much be flawaless! Obviously not! The router that i have is apparantley 5/5 and i really need my wirless connection good through out my house which it should be!

Is there anyway to solve these problems at all! A step-to-step guide that anyone knows? Mainly for my xbox wirless and the 'IP CONFLICT' By the way no more than 2 things are being used at one time, sometimes only xbox at one time.

Please let me no anything i can do, reset settings... ANYTHING!

Thanks for help :)
It sounds like there may be a couple of problems.

Th5 whys problem solvee destop computer was used to establish the link. The modem may have cloned the IP address.
Be sure that your computer is set for DHCP and that the router is in router and not switch mode.
You don't want to have each of your IP request going all the way back to your ISP. They may have a limit on the number of IP or MAC addresses that each account may have. You will want your router issuing IP addresses to your network.

The unit may not be putting out the power that it should or you have strong interference on the channel that it is set for. Use a WiFi mapping tool like Ekahau to see the signal levels and interference in and around your home.

Since this is such a new installation, call your service provider. They should walk you through each step to confirm that their equipment and your setup is correct.