Completely insane keyboard bug?

My friend recently tried playing supermeatboy on her laptop. However, she can't sprint (right arrow + Shift) and jump (space bar) at the same time. If she only runs (arrow to the right) she can jump. She can jump to the left with or without the shift key. I've never heard of anything like this and I'm quite at a loss.

You should do a so-called key rollover test. May be keyboard related, LG

Bad laptop, your problem is based on the fact that keyboards, depending on how they are interconnected, only allow a certain number of simultaneous inputs. With your model, you have virtually saved and the problem can't be solved without connecting a proper keyboard. Controller would be an alternative.