1. Read that just dragging the folder onto the PC won't work, as the Mac-PC indexing of file locations is totally different, so didn't bother with that.
Actually this should work if you drag the whole iTunes folder. Drag the whole folder from drive to drive, to the correct location on the PC.
What are the iTunes library files? - http://support.apple.com/kb/HT1660
iTunes: How to move your music to a new computer [or another drive] - http://support.apple.com/kb/HT4527
do not confuse moving your whole folder and library with moving just media files as in
iTunes for Mac: Moving your iTunes Media folder - http://support.apple.com/kb/HT1449
Macworld - How to transfer iTunes libraries between PC and Mac - http://www.macworld.com/article/46248/2005/08/shiftitunes.html
1. Will work if the media content is inside a folder called iTunes Music or iTunes Media and that folder is inside the main iTunes folder that holds the library database.
If you have a split library (media folder not inside the iTunes folder) there are various tricks to make the library portable again. For an older Mac-based library the database file needs to be renamed from iTunes Library to iTunes Library.itl
On the target system hold down shift as you launch iTunes then Choose the library file on the external drive or just copy it into the User's Music folder.
Alternatively I have a script called FindTracks that might be able to repair the broken links once the library is on the PC.
It seems to have worked, more or less. There is a difference in the number of music files, which I will go look for a script for and see if I can reconcile that- only about 100 out of 30,000 so not too shabby.
For others searching for solutions to this (I searched before posting, but didn't find answers newer than around 2009 for this particular process), I dragged the iTunes/iTunes Media folder to the default iTunes folder on my PC, then went into preferences and told iTunes to look at the default location (for some reason, based on what I'd done before, maybe, it was looking at the external HD which was now unplugged). I then ran
Only oddity besides some missing files is that iTunes seems to think there are 42 missing songs, but I can't find any exclamation points.