This appears to be a graphics card problem often associated with the memory on the card being incorrectly used by the system or perhaps damage from when the old drive failed.
I can only suggest two possible simple solutions:
- Reseat the graphics card(s) and ensure good contacts.
- When the bad screen occurs, turn the PC off at the mains and leave it for a few minutes before trying again.
If neither of the above work you could be into a longer fault finding job, starting with disconnection of all peripherals and checking by reconnection one at a time. I would suggest the HDD first and see if you can get into BIOS alone.