Mac OS X 10.1: Applications Folder Locked or Cannot Be Modified

Symptom

When you drag a file or folder to the Applications folder, an alert box with this message appears:

"The item '<filename>' could not be moved because 'Applications' cannot be modified."

Solution

You should update to Mac OS 10.1.5, then use the Repair Privileges Utility. For information and software download, see technical document 106900, "Mac OS X: About the Repair Privileges Utility".