If you're using Microsoft Excel, it's important to keep your links up to date so that you don't accidentally break them. Here's how to do it:
In the Change Link dialog box, do one of the following:
To update a link to another Microsoft Office program, such as Microsoft Word or PowerPoint, click (Browse for file), locate and select the file that you want to link to, and then click Update. If you want to change how often Excel updates information from this linked file, click Update Values, and then in the list next to When this workbook is opened: , click one of the options.
To update a link to a Web page or an Internet address, type a new address in the Address box under Link To File, or click Change Address. If you want to change how often Excel updates information from this linked file, click Update Values, and then in the list next to When this workbook is opened:, click one of the options.
Click Break Link. This removes all links from this workbook except for any links within formulas.
Click Close without saving. This removes all links from this workbook and does not save any changes that you made in this dialog box.