If the PC is that old, I strongly suggest you just leave it. Bite the bullet and get a new case or least a more newer spacious type, in order to benefit the install of the i3/i5 mtrbd., and start with a better foundation as it were. Not to pick on you, but sometimes its better this way. If you're trying to save costs, then rethink what would happen it after all is said and done, after shoe-honing the new mtrbd. in and maybe finding a PSU that fits, etc., you may bump up against some issue that was easily resolved with a newer case. You can simply just lay the parts out and connect them minus the case to see if they work and final mount them into the Gateway case if you like. Your main consideration is space, will a new mtrbd. fit. Typical OEM based PCs tend to be build with *only* its details in mind, so they don't provide an ease of install for other full-blown upgrades. But, if its generic enough it may be workable. I just find OEM based PCs just get into problems all to easily on the most basic level, usually physical size and/or spacing. What has happened with newer PCs is the basic PC has more cooling and better PSU and ram additions or similar details. All this boils down that a new PC, a DIY should also follow a similar path. A better wattage PSU(amps too) and additional ram slots with leads to better cooling demands, plus any video upgrades. Even if non-gaming use PC, the new i3/i5 will expect no less. If for gaming then you better think all that in mind beforehand.
I want to replace the motherboard on my old Gateway 832GM. I want to replace it with a newer motherboard compatible with 2nd gen. intel i3 or i5. any suggestions since it is an old batx form chassis. if the computer faces you the chassis opens on the right side.