problem with iTunes after upgrading hard drive

Check out the permissions (Not just on the library, also check the preceding folders). For the Users, try removing your admin access, and then re-add it, with read and write.
You can always run Disk Utility, and Repair disk permissions.

Maybe try this:

Make sure itunes is closed (no blue light under the icon)

Hold the Alt key. and then click on itunes. You should see a message that says "Itunes needs a library to continue" Click on choose library, and then navigate to ~/Music/itunes/itunes library (it will have a blue musical note on it)

Choose this library, and see if that works