Certificate validation

Hello,





I recently was trying to get on my laptop using my wireless connection. I kept getting a message saying that it was validating my certificate. I went to netgear and it gave me instructions on what to do when this happens. However, the instructions they gave were probably meant for a recent version of XP because my tabs did not line up with theirs. So I decided to tinker around and somehow changed my computer to Workgroups. I then logged of and went to log back in and it stated it that either my domain or password was incorrect!!!! I dont know what I did, but then I logged in as administrator and password and reset my user password. Now I cant find any of my programs or files. Please help. This was my school computer and has alot of my work and programs downloaded on it that I dont have access to. Can I get this information back and please tell me how to undo the workplace thing under my original domain name. Please advise. thanx