Green Power Supply Why Wont My Computer Start When I Change My Power Supply Settings?

Why wont my computer start when i change my power supply settings? - green power supply

when I put my 115V supply 230V option of custom boot option on my computer, everything that comes, but the green light glows orange, and nothing appears on the screen. I do not need, or at least think I have the added cost to buy a new graphics card, what they need to run only 450W power supply. Suggestions?