I had an Acer TravelMate 4220 WLMi. Core 2 Duo. The motherboard is fried after the fourth time I resoldered the DC connector back on but nevermind that. I acquired a HP compaq nx9010. Pentium 4, for cheap from a friend because the HDD went bad in it. So I replaced it with my own. My HDD is a 2.5 inch Hitachi TravelStar 120GB IDE ATA-7 (NTFS). The HDD I replaced looks to be exactly the same. but when I boot up I'm taken to the "Windows failed to start successfully, blah blah this may be due to recent hardware changes blah blah." I can't boot normally. it freezes as soon as I hit enter. and if I try safe mode it freezes after loading AGPCPQ.SYS. I don't have an XP CD from my old Acer but my friend included the HP's discs and it has an XP cd so booted into the recovery console and I've got CHKDSK /R running right now. I've been reading this topic: techspot.com/vb/topic21511.html but all I can tell is that this seems to be a very specific issue and has a different resolution for everyone so I'm hoping that by posting my specific situation that a solution can be found. EDIT: I forgot to mention that I never had a single problem with the HDD in the Acer. so I'm not really sure why I'm still running chkdsk, just for good measure I guess. but I'm starting to believe the problem is with ACPI. The HP laptop could / probably does, have different power management settings than my Acer? I still have no idea what to do though.