My iMac WiFi is extremely slow!!! Help me fix

Question

I have tried so many things to get my WiFi to run faster than what it is now, It's physically making me impatient. I have done a internet speedtest from the mac and the results are -
Ping - 51ms
Download speed - 0.09mbps
Upload speed - 0.49mbps
I even made a youtube video on what is actually happening.
http://www.youtube.com/watch?v=tjd5k817hn4
What I don't understand is, Why is my macs WiFi so terrible? It's fully connected to the internet.
I have updated the mac and it didn't seem to change in its perfomance.
The iMac is new and it runs everything nice, just the internet is slow as anything.
Now, Let me compare the results to my pc.
Ping - 50ms
Download speed - 3.66 mb/s
Upload speed - 0.778 mb/s
And now my ipad -
Download speed 3.21 mb/s
Upload speed 0.686 mb/s
All these tests were done when there was only ONE device connected to the internet.
Please, Help me fix my problem! I can't even load apples website without waiting 20 minutes!

Answer 1

I spoke to apple yesterday and they run me through a few simple steps.
First I removed all my cables which powers my iMac and I then left the cables unplugged for 15 seconds, After the 15 seconds I reconnected the cables and waited 5 seconds before switch on.
Now, I was instructed to press the following keys.
cmd , alt , R , P
I hold those keys as my mac switches on and you have to keep hold of them until you hear the macs power up sounds twice. Once you hear it twice, let go of the keys you held down whilst you turned on your iMac. I then got told to skip the options what were given to me in the start of turning on the mac, Kind of like factory settings.
I was then told to change my DNS to 8.8.8.8 and save.
Once the DNS was changed I had no improvement in my internet speed what so ever. Now, I was then told to make a test account (login) which had no programs installed the the login. No change again...
The problem is NOT the iMac, It's the router. Because of my router being old'sh and so on, My mac isn't getting the right internet speeds because the firmwire is not up to date with the iMac.
As I spoke to my internet provider Orange or EE (whatever they call themselves now) They said lots of mac and apple users always seem to have problems with old routers. So they're sending me a new one.
My garunteed fix is for the new internet modem to make my connection problems go away.
So guys, if anyone is having the same problem as me, Ring your internet provider BEFORE you ring apple. It will save you time as you have to wait a few days for apple to ring your mobile/phone.
Thank you!
Stan