What does it mean?

i think some thing wrong in RAM or monitor or mother board just check one by one if you r using multiple RAM remove one RAM and test your system do with second one ,if everything correct then just consult with hard ware expert.

obviously it is a bad sign, may be there is some problem with your computers hardware, it is called as dump screen, it occur due to problem with your harddrive or with ram but it is not compulsory to have problem with this both but priority is high. some times the ram does not have enough memory to run big applications so it gives the dump error, may be you have to upgrade your ram, so better is you get checked with some experts.