Difficulty with links - excel resorts to single user

First off, my login name is different from user and the links don't auto-update in the excel when I open it. This dialog box pops up:

Then none of the links are correct as they all use the filepath of:
C:\Users\ADifferentUserFromMe\Folder\Folder\Folder\File.xslx instead of
C:\Users\MyUsername\Folder\Folder\Folder\File.xslx

Thus it says, Source Not Found. Is there any way to fix this? I will have to use this file regularly and others will have to access it.