I have decided to kill my laptop

I am a very frustrated computer semi-geek at the moment. My hubby and I both have a pretty good working knowledge of computers and how to do things with them. This past weekend we decided to buy one of those new dual band routers that use seperate channels for reqular internet and streaming videos, movies, music etc. So I got the new router all hooked up to the 2 wired computers we use for everything and went to work on the lap top. This was last Saturday mind you. I still can not connect to my private network with my lap top. The only 2 ways to get the danged thing to connect to the net is either plug it into the router (which defeats the purpose of having a wireless computer) or using the guest account with my network which is way less secure. I took the lap top over to my brother's house (he has a dual band router as well) I connect fine there. He came over with his pad computer and hooked to my network no problem. I can even get my XBox to connect to the network but not this laptop. According to the forums it is probably a Vista issue and since Microsoft is basicly not supporting Vista much anymore finding a fix through them is probably not going to be easy. Linksys says its my wireless adapter and I need to update the drives (which i have done) and still no go. I have a feeling the only way to use this machine wirelessly again is to upgrade to Windows 7 :(