Much obliged, Dl65.
The other users were very uncareful when opening their PC, leaving standby power on whilst removing and inserting different videocards.
The computer only had a monitor issue that would cause the monitor to flicker when accessing webpages and other Windows related things.
Now that they are done through it, it shows all these errors.
So far they have done:
Leaving standby power on whilst switching videocards. (They claim they did not, however, I caught them red handed.)
I have done for them to see if it would do any good:
Reset BIOS (Removed CMOS battery)
Booted with only the onboard videocard (Even after resetting, a frequency out of range error showed)
Do you think they could have damaged the mainboard beyond repair? Would removing and using the different RAM slots work?
As for the Display memory Read/Write test failure
Even after resetting the BIOS and using only the onboard videocard it still gives the same problem.