I can't install Logic Express 9 on my second machine, which i bought used.

Hi guys, i hope someone can help me out here,

I purchased LE9 and successfully installed it on my Mac Mini a few years ago.

Recently I bought a used Macbook Pro and tried to install LE9 on it but after entering the serial number and about an hour of installation, it failed.

the Macbook Pro i bought came with a bunch of sofwares already installed by the previous owner. is that part of the problem?

i already made sure that my Mac Mini is turned off.

Do i have to hard reset the MacBook Pro?

Thank you

Tim