First, that's a 400 watt PSU. And mabe it will even put 400 watts. That 500 watt rating is a "peak" rating. Ignore it.
Second, if you look really close at the label, the PSU has two 12 volts rails, one with a maximum output of 12 amps, the other 14 amps. Considering that it's a really cheap power supply, I really doubt if the total is 26 amps.
Please find something a little better. I wouldn't put that PSU into your computer.