Windows XP/Installation Problems
Installing to a Third-Party RAID Array 
One problem that comes up from time to time when installing Windows, particularily for performance enthusiasts, is the need to install Windows on a machine that implements a RAID array-- typically either RAID 0, RAID 1, or RAID 0+1. Often, the RAID controller is simply a chip on the motherboard; it may even be embedded in the chipset. If you need to do this, you should follow these steps:
- Hunt for discussions on the web, and in newsgroups, for other people trying to do this with your exact configuration, particularly your exact RAID controller and your firmware version. See what their results have been. Pay close attention to whether or not firmware updates, if available, have been praised or cursed.
- Download the latest firmware for your RAID controller, even if you don't plan to upgrade to it.
- Download the latest XP driver for your RAID controller, unless the discussions you found recommended another version and you agree. If a separate driver is available for use during installation of Windows XP, you want both, on separate floppy disks. Often there is only one.
- If it sounds like you need to, install the firmware update for your controller. Procedures for this vary; you will probably need to be able to boot into DOS. Since you can't easily do this anymore under Windows XP, you may need to make a FreeDOS boot disk; see http://www.freedos.org.
- Shut off the machine and physically attach the drives to the controller, if you haven't already. For RAID-0 or RAID-1, put the drives on master and run only one drive per IDE port-- using slave drives will significantly degrade your performance.
- Power-on the system and initialize the RAID controller's settings to match what you want (see your controller's documentation).
- Reboot with the Windows XP installation CD in the drive, and the BIOS set to boot from the CD-ROM drive.
- Watch the process carefully; when prompted, press F8 to install a third-party RAID or SCSI driver.
- Put in the driver disk you made above.
- Proceed normally through the rest of installation.
- Run burn-in tests on the array.
- Run benchmarks on the array and write down the results for possible future use (such as to compare firmware versions).
Downgrading a Compaq 620 laptop from Windows 7 to XP 
The machine will BSoD when you run the XP install disc, if you don't change the hard drive type in BIOS to IDE.