On another PC, I was running Win 11 with One Drive and Office 2003 with no issue.
On PC with issue, I WAS running Win 10, One Drive (with Doc&DeskTop Synced) and Office 2003 with no issues.
After update of Win 10 PC to Win 11, ....
Tested both Word 2003 and Excell 2003. (Both Office 2003 applications have same issue.)
If I open a file from a window (on either D drive or One Drive), File opens fine, but...
"Save As" brings up a mostly blank window that never populates.
If I hit any button on window Word/Excell stops working.
To Fix, for Win 11, Un-Sync Just OneDrive "DeskTop"
Then, both Excel 2003 and Word 2003 work fine, "Save As" Works.
Steps to fix
Right click little white Cloud on bottom right of task bar
Select "Settings"
Select "Sync and backup"
Turn OFF just "DeskTop"
That simple, took hours to figure out, hope this helps
P.S. Is Anyone willing to part with a legal copy of Office 2007 (with Prod Key) or later? Maybe that version would work better?