Keep loosing connection.

So we recently moved back into our newly remodeled house, and my dad had to use my dell xps laptop to try and set up or wireless router, but it didnt end up working and he used his. After he tampered with my computer it has been loosing connection with almost all outside apps (GW, Msn Im, Itunes store, Internet Explorer etc.) and I am not sure what is wrong with it, they all say check the network connection, but it is at maximum efficency, also I am connected to our wireless and plug in networks, help me so I can play please!

Wireless connections can be affected by cordless phones, microwaves, and some building material. If you have a cordless phone active, move it away from the computer/router, same for microwave. Also try moving it to a different position in the room or house. Be sure your router is up high (not in the basement and preferably closer to the ceiling. Also might want to try different channels for the wireless connection. Channels 1,7,11 (iirc) don't overlap other channels so might help with interference problems.

My room is next to our office, where the router is, its maybe 10 feet away at max. And I dont know howto change the channels, would doing that affect my network at all besides possibly not being interfered with?

Yes changing the channel on the router will help if you're in a neighborhood that contains other wireless networks. If more than 1 router/AP is on the same channel with different SSIDs there will be conflict. Check this out it goes into more detail. http://compnetworking.about.com/od/w...ifichannel.htm
You said you moved back, does this mean you were using the same router before you moved out? If so it could have been damaged in transit.
Does your PC's WZC pick up your network? Can it pick up any other networks? Try to troubleshoot it so you can narrow down your POF(point of failure).

Sorry for all the questions, just need more info to help you out.

By this do you mean you have both wireless and wired networks connected to one computer? If so disable the wireless. They will just have conflicting tcp/ip settings.

Good catch, I didn't remember seeing that. Yeah if you are plugged in WIRED and trying to get a wireless signal, there is an option called "Disable Upon Wired Connect". This makes it so your PC takes the wired not wireless, making it go all wacky.