Office XP Word/Excel/Outlook errors

[ajw]

I am getting the following message when I open a word
document. "This document could not be registered. It will
not be possible to create links from other documents to
this document". I also get the message "Cannot use object
linking and embedding." when I open an Excel spreadsheet.
I also get "This form requires Word as your e-mail
editor, but Word is either busy or cannot be found. The
form will be opened in the Outlook editor instead." when
I try to create a new message using Word as my e-mail
editor.
I am running Office XP SP3 on a W2K SP2 PC. Everything
was working fine and this problem just happened when
opening a document today.

Any help would be appreciated.
ajw