I have an old Leopard MBP and a 2013 Mavericks iMac.

I want to install Mavericks on the Leopard MBP, but had no success since.

Here's what I did.

• I downloaded Mavericks from the MAS on the iMac
• I formatted an 8GB USB drive (naming it Untitled) through Disk Utility
• I ran this in the terminal: sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ Mavericks.app/ --nointeraction
• The creation of the bootable USB was successful, so I booted the MBP using the newly created USB drive
• I formatted the MBP internal HDD via the Disk Utility on the Mavericks drive
• I ran the Mavericks drive installer

Near the end of the Mavericks installation, I ran into the "This copy of the Install OS X Mavericks application can't be verified. It may have been corrupted or tampered with during downloading." error.

I re-downloaded Mavericks from the MAS and tried again; same error.

What should I do now?