Installing XP on Thinkpad T61
Several users have reported getting a "Setup did not find anyhard disk drives installed in your computer." The installer then quits, in order to continue the install you must edit the BIOS. Open the bios (press the blue ThinkVantage button on startup) and change the HDD mode from AHCI to Compatability.
XP will then install without any problems.
It is also possible to keep the disk controller in AHCI mode by integrating the chipset driver in the install CD with nLite. You can also pre-install other drivers, such as the network drivers, eliminating the need to transfer them on a flash drive after installation. Finally, nLite can also integrate service packs, which saves a lot of time spent on Windows Update and rebooting.