The best and safest way is to first try and get all your important data off the drive. Once you have done that, you need to start the drive setup again using XP service pack 2 which is required in order for the operating system to see past 128gb.
In you situation you can use Recover My Files (
www.recovermyfiles.com) to run a Complete Format Recover of the "physical" drive. This should find all your files and display them to you in "folder view" of the results screen.