^^^ Just so you know, I've never had to do this. Try the WiFi app for root users that's in the market. If it won't work when you start it up, go into the settings and change the channel. Repeat until your computer connects. But, that's only if your computer sees your WiFi signal but won't connect, which. I'm assuming is the problem.
If your running Froyo on your phone, don't try Barnacle WiFi app, last time I tried, my computer couldn't enemy see it. They may have fixed it, but not sure. At any rate, I hope this helps.