I am still in the same process with Toshiba Tecra A4 (PTA40U-012009) which can’t boot from it’s HDD due to some reason. The device has an OEM license for MS Windows XP Pro. Additionally it can’t boot from internal CD as it’s not working and it’s not able to boot from any USB devices. So everything I have is an external floppy drive.

Boot floppy images can be obtained here http://old-dos.ru/files/file_764.html – for MS DOS 7.1, http://old-dos.ru/index.php?page=files&mode=files&do=show&id=76#download and http://old-dos.ru/index.php?page=files&mode=files&do=show&id=76#download – for Windows 95

Working USB drivers for DOS (and Win 9x as well) I found at Old-Dos http://old-dos.ru/files/file_640.html

Also an interesting collection of DOS images and tools can be here http://www.multiboot.ru/files.htm

Now I can boot with the floppy and the installation can begin from a USB stick, but still unable to see the harddrive. So it’s an additional piece of work.

Interesting discussions regarding Toshiba and AHCI controllers at Russian forums http://vlab.su/viewtopic.php?f=235&t=84408 and http://forum.oszone.net/thread-135321.html

The most correct driver pack for the Intel chipsets (hopefully for Intel(R) 82801FBM Ultra ATA Storage Controllers) I found at cnet https://download.cnet.com/Chipset-Driver-Intel-Ver-8-3-0-1010-zip/3000-2122_4-162229.html

Collection of drivers for a similar model at Dynabook https://support.dynabook.com/support/modelHome?freeText=893053&osId=3333637, Downdriverlaptop http://downdriverlaptop.blogspot.com/2015/09/toshiba-tecra-a4-drivers.html and Toshiba-drivers https://www.toshiba-drivers.com/download-toshiba/toshiba-pta40e-notebook-drivers-for-windows/ are almost the same and packed in *.exe files. What a mess!

A good aticle regardung integration of drivers to Windows distributive (in Russian, but with pictures) http://acerfans.ru/faq/16-integracija-drajjverov-sata-v.html

To be continued…