Why is my broadband wifi internet access slow with one pc and fine with another?

[transalper]

I have two laptops.

On one the wifi internet is fine. Zippy in fact.

On the other it is really slow. It was fine until a couple weeks ago.

Firefox and IE are both slow. I have cleaned up the computer, deleted old programs, and run spybot and adaware.

What should I try next?
Just to clarify, the PC that is slow now worked fine and had zippy wifi internet until recently. No hardware or software changes were made to the PC or network (modem/router).

[Unregistered]

So, If you have internet connection speed problem with your wireless try with the following steps,
1.)Reset the wireless router by using the power switch on it or by unplugging it and plugging it back in.
2.)Place the wireless router in an ideal location. The higher it is, the better, but don't put it near metal objects.
3.)Get as close as possible to the router with whatever device you're trying to connect.
4.)Keep the router and your connecting device away from other electronics. You should especially keep away from phones, fax machines and microwaves. etc.,
5.)Adjust the Wifi antenna if it has one.
6.)Change the router's channel, especially if other wireless routers are nearby.Following these steps would give you stable internet connection and also increased speed in connection. You can check your internet speed from ScanMySpeed.com before and after following these steps.