Case upgrade for Dell Dimension 4100

i upgraded a friends pc and had the same issue but i solved it very simply see go out and buy a new case but before you do look at the floor model look at the connectors now most cases come with a atx universal plug it's something new i noticed and i just plugged in the plug now depending on the style you might have to reposition ( key it to the terminals) the plug to get the proper sequence but rest assure it is not that difficult did it to a friends dell and it works perfect no problems what so ever give it a try

The easiest thing to do it is look at your motherboard and make a note of the manufacturer and model/version number, as Dell don't make their own boards.

Go to the manufacturers web site and search for the manual probably in PDF format and download it and look for the relevent power button connections.