if you know how to open up your case, you will be able to find that out yourself. here is how. in order for a gt 640 to work in your PC, your motherboard will need to have a PCI express 16 lane. you can just google the term and you will find out what it looks like. then you open up your chassis. if you are able to find the lane on your motherboard, then you will able to install it.
BTW the good thing about GT 640 is that it get all its power from the lane, so there is no extra power connector needed.
Good luck!