I'm sorry to interupt. I recently had a fellow ask me what you are asking. It turns out that he assumed he could just move the file from the backup disk.
If you haven't read the manual or help button file about restoring a backup, you really should.
If you have already read and tried to use those manual/help button instructions, I apologize.
As Ruthie said, I sure hope you included the libraries along with the projects.
If you get totally desperate, TMG has an 80% of so offer for their software. TMG will import projects from UFT backup disks without loss of data. But you will really need to spend some time learning how to use TMG before you enter new data.
And if you didn't backup the libraries with the projects, TMG cannot recover the place names.