So I am ordering a intel 2 core quad Q9100 cpu for my mother's old laptop and i wanted to know if it would work or not. My mother has a dell vostro A860 and from my research i see it is not compatible but i see other laptops with the same Socket P with ddr2 like Dell Precision M4400 that are compatible with the processor and i want to know why my mother's laptop isn't. Thank you very much in advance.
CPU compatibility info for laptops is often difficult to find, often that info isn't published by the laptop manufacturer like it is for retail DIY motherboards. One thing's certain though, just because a particular CPU fits doesn't necessarily mean it's compatible, other Dell laptop models where it is compatible might well have a different motherboard.
I'd make sure that CPU is returnable for a full refund just in case.