I hate to be the bearer of bad news, but I don't think your E-Machine 5260 has a PCI-e slot. You can check though. Open the side panel furthest from where the USB slots are at the back of the computer. Have a look at the motherboard. There will be 2 or 3 long white connectors near the back of the case. These are the PCI slots for add on cards. If you have a PCI-e slot it will be a long black connector between the PCI slots and a device with an aluminium heatsink. click here.