Transferring iTunes Library from Windows to Mac

Hi all those migratory Mac users, I've gotten most things on the Mac set up how I want them; iTunes is causing problems as usual. I have a full copy of my library on my external hard drive, and just want iTunes on the Mac side to recognize it. I get to the "Choose Library," dialog and iTunes says the library file with the .i t l extension is locked. I googled this and found that if I changed some of the folder's attributes, it would work. I did this back on the Windows side, but still no go. Has anyone had this problem before? Thought using my phone would be easier! :)