Unless you have an NVIDIA GTX 970 (or AMD 290) graphics card, an Intel i5 processor (or greater), 8GB or RAM and a number of other specifications, you won't be able to use the Oculus Rift headset with your PC. No matter how hard you try.
Oculus has detailed the first set of Oculus Ready PCs that will be available for pre-order starting February 16th at 8AM PST. The Oculus Ready PCs and Rift bundles will be available from Best Buy, Amazon, and the Microsoft Store, starting at $1499 USD. Unfortunately, you'll have to decide rather quickly if you want an Oculus Ready PC or Rift bundle because that starting price will only be available for a limited time.
All bundles include an Oculus-certified PC and everything that comes with Rift – the headset, sensor, remote, an Xbox One controller,EVE: Valkyrie Founder’s Pack, and Lucky’s Tale!