I was wondering if a DELL motherboards would fit into a different pc case. I was planning on buying a better computer case, but one of my friends told me that it may be possible that the DELL motherboards are custom made to fit only in their cases. Does anyone know if this is true? Any help would be appreciated.

very true!
i just redid a compac 4640 vintage 1997, modified the case to recieve a new amd board
1300 mhz. i cut the rear of the case out, and
and applied a rear panel from a generic case so the new board would fit, and allow add-on cards to fit in their slots. the huge heatsink fan would not allow the new power supply to be mounted in its original position, so i mounted a new supply with blue light on the floor of the case, and cut a portion of the side panel out for the power supply and its fan. the start switch is on the rear of the case, and of course it powers down and shuts off automatically.
so, anyway, a new board for your case would would need to fit the case. unless you get out the tools. i only did my project , just to see if i could.

Also, Dell has used non standard power supplies.

They are propritary meaning that if you plug a standard ATX power supply into them, they will fry. Also, all the front panel wiring is made into a ribbon cable so it is not easily plugged into a regular case.

I did it with mine but it took time and does not look pretty inside.

Jimi_l

Not worth the trouble.