Corrupt driver/software??

Hello to everyone. I’m in a bit of a pickle. I downloaded a program called hide and protect. It as intended for my external HD so people could not access it. Well now I can not access it. I uninstalled the software not realizing I locked the hard drive. So, under Windows XP I cannot navigate the HD. However if I open it through Vista I can. I deleted all traces of the program in the registry, and I also reinstalled it to try and unlock it, but It won’t show the drive under the software. However I can see it under My Computer, and Disk Management, but it shows it as 0GB of 0GB of space??? Any ideas?? Like I said I can open it in Vista, but not on XP.(Dual boot machine) Any help would be greatly appreciated.