Why can't I repair and restore my HP 110 Netbook?

Episode 890 (19:33)

Tess from Burbank, CA
HP 110 Netbook

Tess got an HP 110 Netbook from someone who replaced the hard drive with a different one. Now it's giving her errors that she's missing the boot manager, and is not able to be repaired or restored. Leo suspects that whatever the previous owner did when installing the new drive made it nearly impossible to recover.

The chatroom says she can put "GAG", a free boot manager, on her computer to fix it. She can load it onto a USB key, boot to that key, and then it will put this boot manager on her system.