Internet Fast on Some devices but slow on others?

I recently got a new internet modem and it is super fast but only on some devices like my iMac, MacBook and iPhone but won't go that fast at all when is being used by my windows laptop or iPads. Can someone please tell me how to fix this As soon as possible I would really appreciate it!

What speed is your modem/router? B? G? N? Dual?
~
What speed are the various devices, each one? B? G? N?

Perhaps when you know what each device operates at & you know more about your router you'll have your answer.

If it is not a dual speed router, all devices run at the lowest speed of any connected device.

  • Wi-Fi slow on Windows, fast on Apple devices? Hi. For a while now my Wi-Fi Internet has been really slow on my PC (Win Vista) and laptop (Win XP), even if I connect them to the Internet by a LAN cable. I know it's old OSs but it was perfectly fine up until a couple of months ago. Speedtest.net won't even open now. On my Apple devices, however, iPhone 5 and iPad mini it works great. I can watch movies and do anything I want. Can anyone point me in the right direction please?
  • Why some old people difficulty with electronic devices, mobile, computers, internet? My mom difficult uses an iPhone Bizarre Seems very complex for her Difficulty make a call Difficulty make a call
  • Laptop gets slow internet connection, yet all my other devices get it at full speed? This never used to be an issue up until a few weeks ago, we had a 60MB connection that was buffed up to 100, my laptop used to download at around 5.5 - 6MB per second, whereas now its between 2 and 2.5, yet my iphone and all other computers in the house still get the full speed. I have checked the drivers which are all up to date, I can't discover the problem, what could be causing this? And how can I go about solving it?
  • Iphone problem! I can't get text messages from some people, but can from others? I have a iphone 4, running on the latest version; ios6.0.1? I believe if I'm not mistaken. I use it on t-mobile, i believe it is factory unlocked. I do use imessage, i attempted to turn it off and see if the person could text me again; still haven't received. I do receive text message from some people. I restarted my phone a couple of times. has anyone had this problem? If so what should i problem check to try to fix