MySQL installation gone bad, how to fix?

Hi, I have a MySQL 5.1.45 (32-bit) that I backed up via MySQLWorkbench 5.2 CE. This was running under Vista with SP2, and all subsequent updates.

I later found out that I missed that something very minute in the MySQL’s own databases had gone wrong in the backup - i.e. my “own” databases are still good.

The reason for doing all this was to install a much newer release which has features I would like to use. And that version was installed. According to tests done nothing needed to be fixed for the new version - the database is simple but with 3.5 million records.

I have the old (5.1.45) installation still in place but it refuses to start - probably because of the new .ini file no longer matching.

What I would like to do is to copy all of that installation to a “new” computer and basically reinstall 5.1.45 and replace the database file.

Is this possible or is there another way to do this - I have all the user passwords incl root manually noted?

Any help is REALLY APPRECIATED…

Bagtjesen