I am looking to rebuild most of my computer only keeping a few things, but I am upgrading my motherboard. Im pretty sure this is my current http://www.intel.com/products/motherboard/D945PLRN/index.htm

This is the one that I am looking to buy http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=3528992&CatId=2406

how can I tell if this will fit in my current case? also does anything else matter with case size, or is it just the motherboard I need to worry about?

First off, what your looking to buy is no longer available. Second.....with a brief look at the two I do not believe it would work. HOWEVER I may be wrong. Case size DOES make a difference on heat dissapation, and keep in mind the new the CPU, and the more power, the more heat it produces. So more air to circulate is better for the components. Although most comuter components are getting smaller, they are also getting better, and more demanding on the cooling measures. Unless your going liquid (which you owuld need space for the tubing and machinery as well) having more air circulation is better for components.

Just make sure the case you get can mount your motherboard....and extra components.

ty ty , I saw that i couldnt get it anymore last night and that made me pretty mad lol, but oh well I found something else.

you are wondering if you need a new case and show a picture of the motherboard ,and its a desktop board is it in a tower style or flat top case.
anyway ,you would be much better off getting a new case and power supply for your dual core ,than trying to use the old one .

the mobo specs usually state the size of it asswell.So if the size is right and air circulation, obviously appropriate fans then its all good

if its a case from an OEM like Dell or HP then it wont fit. They use nonstandard components.

if its a case from an OEM like Dell or HP then it wont fit. They use nonstandard components.

i have a customers E-Machine and the board is gone ,first time i worked a emachine ,I need to change the board ,will be using a no-emachine board what nonstandard components should i be looking for

well dell cases for example, are BTX. Also, they dont use standard switch headers for power , reset etc... the front panel has a load of diagnostic lights and is connected to the motherboard by a proprietartry interface which looks like a small IDE type cable.