Mother Board form factor

how can i tell what mobo form i have since alot few of you guys told me would be easier to just get a new case so i can get a bigger power supply

 

These days there are 2 common form factors. ATX and mATX, the "m" is for 'mini' or 'micro'. There are MANY other form factors, but these are the most common. More info on all the different motherboard form factors can be found at this link.

This is an ATX form factor motherboard:
http://www.malabs.com/assets/products/MB-M4N78-P_LG.gif

This is a mATX form factor motherboard:
http://www.malabs.com/assets/products/MB-M4A78EM_LG.gif

Notice the difference in the spacing between the screws, especially on the side where the keyboard/mouse/monitor/USB ports are. The smaller mATX board naturally has a smaller space between the 'middle' screw (this is the screw hole next to the speaker/mic ports), and the screw on the left side in the pictures above. All cases manufactured in the past few years can usually accomodate both form factors, unless the case is particularly small. When looking to buy a case, simply check the spec sheet and it should list all the different form factor that are compatible with that case.

 

thanks