Can a motherboard from a e machines computer replace a motherboard in a gateway computer?

Probably yes, but you're in for more than you think if this is your first time doing this.

There are only a few common "form factors" that motherboards use. They are standard across manufacturers. So, if your two mother boards are the same form factor, you can physically mount the eMachines motherboard into the Gateway computer or vice versa.

The first time you start up Windows though, it's going to have a fit. It will need to change out the drivers for all of the new hardware that it finds. This is a long and frustrating process and often doesn't work at all. You'd probably be better off just formatting the hard drive and installing Windows from scratch.

Before you dive into this, make sure that your hardware really is bad. Often that kind of error comes from something simple like a RAM chip coming loose. Open your computer and make sure that all of the RAM chips and other expansion cards are well-seated in their slots. If it still won't work, find a computer savvy buddy to take a look at it.

At first my thoughts are power supply, but since you say that there is juice going to the computer for a second, I think it's a motherboard problem. How many watts is the power supply?

No but you can if both the motherboards support the processors.If it is a hardware error then reinstall the XP.

It is a wate to interchange mobos

Think it helps:)

Your motherboard has no trouble. Try changing RAM or HDD. The hardware error is either in RAM or HDD.

If the sockets 478,774 939,AM,AM2,RAM,CPU are the same

YES.

Then -will your mother board support that CPU even if its the same socket?

Emashine P4 3.0 and Gateway mother board only supports up to P4 2.4-FORGET IT.