Upgrade Qustions

[Unhappycamper]

 I have an old pc from 2009 that I would like to upgrade to something that can handle most games tweaked down a bit. My issue is I am quite new and have never upgraded, or built a pc before, so I need some guidance of weather the parts I want will be compatible. The parts I want to install are:-New hard drive http://www.newegg.ca/Product/Product.aspx?Item=N82E16822148912

      -New gpu gtx 750 http://www.newegg.ca/Product/Product.aspx?Item=N82E16814500333CVF&cm_re=gtx_750-_-14-500-333CVF-_-Product

 

Old pc specs http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&docname=c01949155#N1133

 

Mother board

• Manufacturer: Pegatron

• Form factor: microATX - 24.4 cm (9.6 inches) x 24.4 cm (9.6 inches)

• Chipset: NVIDIA GeForce 9100

• Memory sockets: 4 x DDR3

• Front side bus speeds: 5200MT/s (5.2 GT/s)

• Processor socket: AM3

• Expansion Slots:
  • 1 PCI Express x16 slot for graphics card

  • 2 PCI Express x1 slots

  • 1 PCI slot

  • 1 PCI Express x1 minicard slot

• 300W power supply

What I really want to know is will I be able to power and fit a gpu with pci 3.0 on a older mother board with 

• 1 PCI Express x16 slot for graphics card