After the computer has been shut down and left off when it is turned back on it will not boot. i have to take all usb devices off the mobo connector and then restart. once i do that and push reset the computer has no issue posting. I dont know what the trouble could be and hope you can help me with this.

A long shot - what boot order have you set in BIOS? 8O

1: sata hd
2: dvd ide

thats all i have for boot drives, also have legacy usb enabled

What USB devices do you have plugged into the machine?? you might want to try removing them one at a time to see if it is one of those with the issue.. My sister had this problem and it was her damn iPod that was always plugged in...
-Good luck

Maybe a overclocking error. Power off, remove power cable, clear your CMOS and power on again. Remeber set your bios settings back to default.