When Mike Shilton needs to restore the links to referenced files in many files at one time, he uses the Reference Manager program.

"When servers are updated and drive letters change, you often need to reset the folder paths to your externally referenced files. Using relative paths can help, providing all externally referenced files are located in the same folder or subfolders of the current drawing file. However, when you have multiple externally referenced files in different locations, instead of reloading all of the references in the drawing manually, try using the Autodesk Reference Manager, which is accessible from Program Files. This external Autodesk utility is available with all full versions of AutoCAD (not LT). It allows you to open multiple drawings and quickly redefine the saved paths of externally referenced files in multiple drawings, including drawings, images, shape files, etc. These changes are saved back to the drawing and replace the currently saved paths. It's not perfect, and it can be a bit cumbersome, but it can also save you a lot of time."

Notes from Cadalyst Tip Patrol: The Reference Manager can be very useful. One of the best features is that you can re-reference more than one file at a time. That means that if you have to change the path of a project folder, you can repath every file at one time. Load every file into the list by using the Add File button. Double-click the referenced file to change its path. Browse to the file or type in the new path. If that referenced file exists in more than one file in your list and you activated all files in your list, then the xref will be repathed in every file where it is referenced. Click the Apply Changes button to save your files. This is also a way to batch save files.

Tested in AutoCAD 2010