you really must be desperate to make a paper weight out of your Prevail ( since you don't believe any of us here )..........
I posted a possible solution on how you can fix your USB problem in a previous thread of yours..... And if this computer is really that badly screwed up that you can't get your Prevail to connect, heck, go to a neighbor or a friend and use their comp.......... just install the drivers, root the phone and your out there again...... Takes less then 15 minutes to do that !!
And if there is NOOOOO Windows computer around your for like 1000 miles, contact these people, they will root your Prevail for you !! Samsung Phones - Samsung Galaxy Prevail - MobileTechVideos.COM