Need help for optimal gaming experience

Highlighted
Kilobyte Kid

Need help for optimal gaming experience

[ Edited ]

I wish to upgrade my graphics card from a GEFORCE GTX 745 4GB to a 970. However, I don't know what I would need to upgrade, except for additional RAM and bigger power supply, to make this happen. Below are my current specs. What do you all suggest? Keep it simple terms for me as I no computer expert. I would to upgrade if possble without buy a new computer but I will still take the suggestion if it would be more to my interest to buy a new one. I can't build..I dont have the knowledge base for that. 

 

Windows 7 Home Premium 64
• 4th Generation Intel(R) Core(TM) i7-4790 processor quad-core [3.6GHz, 8MB Shared Cache]
• 4GB Nvidia GeForce GTX 745 [DVI, HDMI, DP, DVI to VGA adapter]
• 8GB DDR3-1600MHz [1 DIMM ]
• 1TB 7200 RPM SATA Hard Drive
 
• 15-in-1 Multi-slot Media Card Reader, 4 USB Ports (Front/Top), Audio [Front 2USB2.0, Top 2USB3.0]
• No TV Tuner Card
• Integrated Sound, Envy Audio; Beats Audio
• HP USB keyboard and optical mouse
• HP WLAN 802.11 b/g/n 1x1 MCard BT
• 300W Power supply
 
Possible motherboard: 
 
  • Manufacturer: Pegatron
  • Manufacturer name: IPM87-MP
  • HP name: Memphis-B
 
Fire Away!