Hi and welcome to the forum,
does your PC meet the minimum requirements for ZorinOS?:
For the GNOME based versions (non Lite):
700 MHz x86 processor
3GB of Hard Drive space
376 MB of system memory (RAM)
Graphics card capable of 640x480 resolution
Sound card
For the LXDE based versions (Lite):
266 MHz x86 processor
2GB of Hard Drive space
128 MB of system memory (RAM)
Graphics card capable of 640x480 resolution
Sound card
Have you tried booting into recovery mode and running "
dpkg", see this guide and the section about broken files:
(Network cable required!!!!!)
viewtopic.php?f=6&t=2247Let us know if this helps you.
Regards Wolfman