Is the Windows Vista Repair nothing but a scam?

This thing pop up on my desktop and it never allow me to click it off. The bottom right of my desktop show warning about "no Ram space left or damaged cluster" I try going on Window Defenders to see whats the problem is and every-time I do that, it click off. Also, I keep getting Hard drive failure on my desktop and if I don't do anything they force me to log off. Its also trying me to buy something advance to fix the problem but I don't believe it.