If I try to run Delphi 7, I get this frightening message:

Register Delphi
Borland license information was found, but it is not valid for
Delphi.
You can not run Delphi without this information.Click the 'Exit' button to exit Delphi.
[Exit]
Delphi was running fine this morning, but choked when I tried to load the project I'm working on.
- I reinstalled Delphi from the original disk: same message.
- I have just done a system restore from a few days ago: same message.
I don't know why.