I keep get a runtime error it says it has to do with the Fallout New Vegas EXE. I for the life do not know why it was fine i was playing for 2 hours straight and i stop to check something on facebook and i started to play again and now it say i got a runtime error out of no please help.

Have a look at this http://www.computerhope.com/issues/ch000380.htm it might help you. First thing first restart the computer. I never this issue before. Touch wood.