Reconnecting Internet on Wired Devices & Wifi Settings?

[679]

I recently changed my encryption settings for our home wifi, but i've since been having issues connecting to the webpage that comes from typing your IP into the URL Bar, and issues connecting to the wifi as well.

I've got 3 computers that the wifi is currently being used most on,
Computer 1 (Mother's in this case) is wired to the modem. (Windows Vista)
Computer 2 (Mine) is using a wireless adapter/ internet connection key. (Windows 7)
Computer 3 (Extra) is a Laptop and has wireless connection built into it. (Windows 7)
I cannot get Computers 1 or 3 to connect to the modem.

Exactly what I did was go to my IP address in my browser, Wireless Security Settings, and made an encryption key. I didn't change any other settings, that is the only thing i did, but right after when it disconnects all users and they have to reconnect, I connected on Computer 2 and after like a minute it connected, tried to connect on Computer 1 and found there wasn't a generic list of networks in the area to connect to and was stumped because i don't know much about how to connect when it's already a wired network, and tried to connect on Computer 3 and got it connected to my network, but it still says that it has limited to no internet access.

Information that might be helpful to helping me figure this out:
My user/password is not admin/admin, that's already long changed, no need to let me know the default or remind me to change that. .
Security Type: WPA-Personal
Encryption Type: TKIP
I know how to find my IP address, I don't need any help there.

This is my rewording of the last question i posted, but on that one you guys kept saying to open my IP address in the browser, and since i've changed the Encryption Key/Wifi Password to me my browser will not connect to that page, so i kind of can't do that.

Questions:
-Can i connect to the internet manually on a computer (Computer 1) that is wired to the modem? How?
-Why could my laptop (Computer 3) and desktop (Computer 2), who have the same Networks and Sharing Center options, have one that connects and one that doesnt?
-Is there any other way to alter my modem's settings for wifi OTHER than going to my IP address in my browser? If so, how could i go about doing so and reverting what i've done (if that becomes the last resort)?

Please help me figure this out! It's frustrating me to the extreme, it seemed really simple to do but now it's just been so problematic! Thanks for your time though!

[hbk]

>Check if MAC Address blocking is enabled or see if pc ips are blocked in router configuration page
>if there is no issue with MAC address blocking then try changing wireless channel to 9 or 1
>even if wired is not connecting then u can try resetting the router and reconfigure and see if that helps
>if still same try updating firmware for router

Hope it helps