NO, you're doing it all wrong. L-Ret and R-Ret are AUDIO CABLE WIRES! You NEVER need those connected to ANYTHING to make the computer operational.
Your front panel wires are JUST LIKE YOU SHOWED THEM:
Power LED (1-3) are for the light on the front to show the system is powered up, this isn't needed to make the system boot, but is handy for showing it's on.
HDD LED is for the hard drive light on the front panel. It's also not needed to make the system work, but should flash when your hard drive is being accessed.
DC SW is for the power button, and IS needed to turn the system on.
DISCONNECT EVERYTHING as you have it all wrong, then put the Power Switch wires (PWR SW) on the DC SW.
The order is: PWR LED on pins 1 and 3, HDD LED on pins 5 and 6, PWR SW on pins 7 and 8.