Can you use a dell inspiron 5100 p4 motherboard pn 5w609 to replace a dell inspiron 1100 p4 motherboard pn 5w610?

Answer 1

Sure can....have done so...you may find the Wifi card from one motherboard or graphics chip doesn't plug into the other so make sure you get the graphics chip with the motherboard.

The answer is a qualified yes. The 5100 motherboard does fit in the 1100 case and will mount with the same holes. However, you must also replace the power supply, graphics card, CPU, CPU fan and a couple of other parts. So, after having done all this you might as well have started with a new computer.