How do i uninstall UBUNTU without emptying the partition?

i have XP and ubuntu on dual boot with Ubuntu's GRUB. I originally put some files on the HD before I had ubuntu on it, and after installing ubuntu I'm not able to access those files! I need a way to remove Ubuntu or find mt files as I'm not able to get them through Ubuntu gui or XP GUI. There is a folder which may have it in the file system of Ubuntu BUT it's not allowing me to open it, it says I dont have the right permissions. Please HELP!