Hello,can all of emachine et1331 tell me what the power of stock psu in emachine et1331(because it is no list there),can i do well with gt 220 ir gt 240
You can open your case and it should tell right on the side of the psu what the wattage is of your power supply. I believe the GT220 doesn't require an additional 6 pin PCIe connector. But the GT240 depending on the brand you get may or may not require the 6 pin connection.
But either way, most likely your computer will be able to run those cards (if you have a PCIe x16 slot) and you can always buy a molex to 6 pin PCIe adapter if you psu doesn't have it.