Can I install a gt 640 1gb ddr5 in my pc?

My PC is a Lenovo Thinkcentre M57 6066
Specs:
Intel 2 Quad processor 2.40 GHz
4 GB RAM DDR2
Intel Q35 express chipset family
Slots
Slot 1: full length, low profile-height 32-bit PCI 2.3 (5v)
Slot 2: half-length, low profile-height, PCI Express x16
ACPI 280 Watt power supply with manual voltage selection switch
Automatic 50/60 Hz input frequency switching
150 gb hard disk 7200RPM

If there's a better graphics card than the gt 640 and is capable of running in my pc please tell

Syed Ziyad Tariq

A GT640 requires a system PSU of 350W, your 280W is a bit low.
Your main problem is that you can only use a half-height (low profile), half length video card. There are no "powerful" video cards that meet that configuration, just low end video cards like the GT610, 620 series

Adrian