You want to disable the encryption on the device itself not within Windows. For what you pulled up, you should set "Infrastructure"
You were "Media State Disconnected," last time you ran IPCONFIG /ALL
If you could run that again, it would be great.
Regardless, what you want to do is refer to your manual that came with your WRT54G2 V1 and login to it through the web interface and manage the encryption through there.
The book will have the IP address of the device as well as the username/password; though, you have provided us enough information to make an educated guess.
If you do IPCONFIG
Then find the IP Address Next to "Default Gateway," it should be the management IP of the device, too.
For instance:
Default Gateway . . . . . . . . . : 192.168.1.1
If that is the case, put "http://192.168.1.1" into your web browser as a URL (without the quotes)
You will be prompted for a Username/Password, which would require a lot of digging or the manual to be certain; however, almost all Linksys devices have a blank username and the password is typically "admin" (no quotes), but this is not a rule only a common practice.
Now that you are only 15, I am going to do a lilttle bit of research for you to deomonstrate the importance of research (and keeping manuals).
I did a Google Search for Linksys
I Clicked on Support
I Selected your Model Number
I Put in Version 1 (V1)
Then I found your firmware and an owners manual.
Drumroll:
http://downloads.linksysbycisco.com/...UG_C%20web.pdf
Read that.. It will totally walk you through configureing your device :-)
You will also learn a great deal about hom/home-office networking. If you read it and have any questions, we are here to help. You can also search the Internet and will find a lot about any network Topic. For instance, say you are interested in QoS... an Internet search will tell you all about Quality of Service...
There is also a "XP, Vista Setup Wizard" Ver.4.9.9020, but it is huge at 104 MB and should be un-necceary; since, WiFi is generally very easy to configure, but it is there for you if you would like to try it.
There is probably also a support number on the box, on your manual, or in that PDF manual I attached. If not, you can probably find the Contact info online by doing a little research. Regardless, if the device is new enough, you should have technical support. These people sit around all day (and night) just waiting for their phone to ring, so they can help you setup your router. They typically do not have the same level of experience many of us do in Networking; however, they know their individual products very well and have a lot of practice working through the common problems people experience. You can give them a call with your Serial Number ready.