Hello everyone... I've been searching all over the Internet trying to see if anyone had any experience with upgrading laptops. This is my first laptop which I've now had about a year. I got a Celeron M 430 with my Compaq Presario V3000T at the time. I recently upgraded the laptop to a core solo to gain the EIST ability and am now getting even better battery life than when I first got the laptop even though the battery has degraded about 15% over the last year. I was getting about 6.5 hours originally and am now getting about 7 hours. I had spoken with their tech support prior to purchasing the core solo and was assured that this laptop would support core solos and core duos. They also provided their own manual to assist me in taking it apart and putting it back together. I then received a core duo to upgrade to. I made sure that both of these processors were listed in the manual for this laptop and and the technicians assured it would work. The motherboard has the 945GM chipset which is sufficient for the core duo, and I think even the core 2 series as well. However, I've tried installing the core duo twice now and gotten the same result both times. The screen remains blank and while the lights come on, the cpu fan spins, the hard drive spins, but nothing else happens. The BIOS won't post... nothing... My former CPUs both work when I put them in. The person I bought the duo from has said he would take it back but assures me that he tested it prior to shipping and that it was fully functional. Indeed, there doesn't appear to be any damage to the CPU. The die isn't cracked and none of the pins are bent. I have read how HP has been disabling functionality of things with their BIOS. Apparently the Vista Upgrade is one example. Another is with the wireless card stuff. Is it possible that they have certain elements disabled in the BIOS to prevent a core duo from working properly? Could they be doing this somehow to ensure customers won't buy cheap models and then upgrade them themselves? I also have noticed that I hear a strange noise from the laptop, but only when the cpu is not under load and when the operating system is loaded. The sound isn't coming from the hard drive or fan. I can only hear it if I put my ear up to the fan hole. Its not a constant sound either. I have no idea what it is and I don't recall hearing it with the Celeron M 430. Oh, I also downloaded the Intel Centrino Mobile Technology Test utility which said that the CPU passed, but not the chipset or wireless. I can understand why the wireless wouldn't. It's the broadcom network adapter. The chipset, however, I don't understand. This laptop has the 945GM chipset. This laptop model had the option of core solos, core duos, or celeron ms. Granted, they do use a "defeatured" motherboard for the celeron Ms, but their techs have assured me repeatedly that this laptop would run a core duo.