sure why not? no problem I already did my insipron 1440 pentium dual core T4400 800 fsb 1mb cache upgraded to core 2 duo P8700 1066 mhz fsb 3 mb cache super fast processor, but make sure you update the bios to A07 version before you replace the processor. infact all dell inspiron 1440 motherboard series will support the T and the P core 2 processor up to p9000 series 6mb cache 1066 mhz fsb socket P (478) the Txxxx cpu and the Pxxxx cpu are the same socket. some people call socket P and some call socket 478, but in generally they are the same socket ,so don't get confused. Remember! all the Txxxx cpu series take 35 watts(thermal power consumption) and all the Pxxxx cpu series take only 25 watts(thermal power consumption) and also super fast processor, does that help answer your question? I guess I am the first one tried to upgrade the laptop processors right?