WinXP/Word 2000

I have a user who was sitting at PC A and "reviewing" a document from a
shared drive.

She now is sitting at PC B.

When she opens the same document, she cannot change her previous
reviews, and her new reviews are in a different color.

It is as though Word believes here to be a different editor.

How can I get PC B to see her as the same editor as she was at PC A???

Thanks