Access database lost workgroupfile

[Frans C]

Not a VB question, but I hope you forgive me this time.

A colleage of mine (a system administrator) created a database with cd information when he worked for his former employer.
He did this with MS Access 2000, and he put the database on his notebook. At one moment he suddenly needed to log into the database. He doesn't remember what he did to cause this.
He said he logged in with username administrator and a blank password.

When he quit his job, he had to return his notebook, so he copied the mdb file to another computer. The notebook got formatted.

Unfortunately he didn't copy the mdw file, so now he can't open the database anymore.

Access gives the message:
You do not have the necessary permissions to use the "...\.CD-Software.mdb" object. Have your system administrator or the person who created this object establish the appropriate permissions for you.

I tried importing or linking the tables into another database, but this gives the same error message.

I tried adding a user with the name "administrator" to my system.mdw, but this has no effect.

I tried opening the mdb with a hex editor, but there is no usable, readable information.

When I try to open an ADO connection, and I use usernam "admin", I get the same error.

When I try to connect with username "administrator", I get the message:
Cannot start your application. The workgroup information file is missing or opened exclusively by another user.

OK, this is logical, but at least I know the username is correct.

Is there anybody who has an idea about how to recover the data?