Computer at the end.. and me too..

Hello guys. I have a problem with my computer and I don’t know how to help myself anymore. It’s very quickly overloaded and just mucking around. Sometimes the image is simply black and at the top of the screen appear vertical green strokes. Then it often ignores clicks from the mouse ect. Bluescreen comes in minute stacks. I’ve already formatted tens of times and tried different operating systems. At WinXP there’s no holding at all… there he totally acknowledges the service t. At ME (what I just got on it) it’s just like that. Have no idea what’s going on. Is the junk? Is the hardware in the bucket or what can all this have for reasons? Amd 1600+ XP Geforce 2Ti Elite Group k7 Board 256DDR plz help