Stuck at "Still waiting for root device" - tried almost everything.

[billmavra]

Guys i have also tried everything i found on the internet in general but i am "Still waiting for root device".. Also apart from the usb attempts i burned a DVD DL and booted from it with no luck... It shows me the corrupt icon (circle with the line in it) and also when booting from DVD i cannot add bootflags....I have an Asus G20 with i7 4790, HD 4600 + gtx 760...if you need any information in order to help me please ask for them... Thank you in advanced...