Ater my computer crashed and I replaced the motherboard (faulty IDE controller), I found it impossible to install Windows XP on my new setup. I determined that there were no hardware problems, so the fault was probably with the OS, APIC mode settings or with my computer's problem with recognizing the XP installation sequence. Here's how I was able to install WinXP: First, clear the CMOS on the motherboard (usually with a jumper). Set FSB at lowest setting, also with motherboard jumper. Make sure that the only components on the computer are the basics: CPU, memory, hard drive, floppy drive and CD ROM. Use only one stick of memory, preferably one that has shown to work properly when the computer was working. Fire up the computer and go into BIOS setup. Set boot sequence in Advanced BIOS to floppy, CD ROM and hard drive (SCSI with SATA drives). Disable level 1 and level 2 cache (really important). Disable APIC mode. Go into Advanced Chipset features and set CPU external frequency to the lowest setting. Set system performance to optimal. Leave memory frequency at SPD. The reason for doing this is to get the computer to operate slowly. The reason for getting it to slow down is that, for some reason on some computers (this is the second time it has happened to me using an nforce chipset), you get zero time to hit the enter button after the "Setup Is Starting Windows" and "Processing Information File" is presented. With a slower computer, you have time to start the sequence of formatting and preliminary file installation--you can hit that button and it works! Here's where the rub comes in: the installation of the primary files will take an incredible amount of time. It took my computer about eight hours to just accomplish this phase of installation. BUT . . . the files will install. My idea was to let the installation go overnight while placing a floppy in the drive so that the file install phase comes to a halt by itself, unattended. I got up in the morning and instead of taking the floppy out and hitting "ANY KEY" to proceed, I hit Alt/Ctrl/Delete. That brought me to the BIOS after hitting the Delete key. In the BIOS, I returned every setting to default (optimum, whatever) and then I reset the necessary jumpers. After this was done, the computer automatically performed the rest of the installation without need of intervention. What I've discovered since performing these operations is that my problem is not unique--there are lots of people on this and other web sites looking for a cure to this particular predicament. I am in the process of relaying the method I used successfully to all of these web sites :hotbounce . I am really good at understanding computers, especially hardware issues. But this problem threw me for a loop. The only thing I knew I needed to do to try and solve it was to slow down the computer so that I had time to hit the appropriate buttons. And it worked! I hope you all find this information useful (I'm pretty sure my "cure" will never end up on Microsoft's troubleshooting web site!).