[Speedz]

Check the channel of any cordless phones in the house and the channel your router uses.

Routers that are using the 2.x ghz range can get blocked or cross noise from cordless phone since they share the same radio wave length.

I had to manually set the router channel since usually it is defaulted to a "pick any state". Then hit a channel button on my cordless phones till the noise stopped dropping my wireless computers of the network.

Give that a shot. Also I have that same issue with my ISP. I am on a 900mhz WISP (wireless internet service provider) and ANYONE in relative proximity to me and the tower with a cordless phone or 2 way radios drops me in exactly the same way.

Also, What router do you have, are there other computers on your wireless network, how old is your windows install.

Issues with packet loss can also rise out of 2 computers that have the same type of network card chipset (check drivers for name and rev#)
I have also fixed this issue by switching network cards in one machine.

Lastly, routers and network cards go bad due to various factors. Dirty power being one of them (meaning power fluctuates in hz and voltage). May also try switching out equipment. Trying a wired connection will tell you if your PC is having the issue or if there is "something" interfering wirelessly. But it won't really tell you what specific type of issue you are having with wireless as there are many factors there that can go wrong. But I still would test wired to rule things out before you take any expensive or drastic steps.

Another thing you can do is change your router security, someone could have gotten into it and is getting free internet and messin up your bandwidth?

Change connection info to your router, password and maybe encryption type.