Slow internet on only one of my laptops?

your computer fight be infected. go through your programs manually and remove adware, spyware etc. use this site: http://www.shouldiremoveit.com/ it could also be the limited ammount of bandwidth on your network. i would try the laptop without the other computers connected to see if it is an upstream bandwidth issue. if not, it could be DNS issues or IP address conflicts.

Are you using Internet Explorer? If so I recommend you stop... Use Google Chrome or Mozilla Firefox. IE is often times much slower than the other browsers.

Most browsers offer a "safe mode" or a mode that disables all add-ons. It could be that an extensions or add-on is not working properly and is causing your browser to act slowly. This mode should be installed automatically by default with whatever browser you use.

Have you tried plugging in the computer directly to your modem or router via ethernet cable? This will help determine if it is computer that is slow, or possibly an issue with you wireless card (although it is unlikely).

Check out speedtest.net. I recommend trying it on both computers and seeing if the speeds are the same (obviously they should be). If not, it's an issue with your hardware.

It couldn't hurt to use a program such as CCleaner might help to clean out some junk files that might be slowing down your computer and browser as well, and also you may want to run a virus scans (hopefully you have anti-virus software, but if not check out malware-bytes)

I hope this helps!

Malware.

Use Combofix. Here,

http://www.bleepingcomputer.com/download/combofix/

After running it, try to compare your laptop again..

If it doesnt resolve it, update your ethernet/network controller drivers.