So I opened my powertower and found the power lead which connects str8 into the atx power supply and has a p9 and p8 connection at the end and most of the colours match at both connections (My power tower lead looks just like this http://www.quietpc.com/uk/images/atatxsm.jpg) is this a atx2at adaptor I already have or it it just a standard powertower power lead.
!!!
I never noticed that myself. Just shined a flashlight into my own powertower and I'm looking at the label on my PSU:
"Octek X20 ATX Power Supply Model No.: X20"
This psu what originally came with my PowerTower, and my power cabling looks just like yours!