computer power for video editing

I currently have an old updated; now outdated, AMD Athlon 64 x2 Dual Core 2.6 Ghz, 4 GB Ram, Win 10 home 64 bit with newer GeForce GTX 750 1 gig w/ HDMI out to my monitor. My problem is probably obvious..not enough power to edit or run HD video. It plays "okay" in 720p, but when I go to 1080p...