*Be sure your computer supports booting from an SD card before trying*
Create a bootable SD card
First, you need a way to boot the computer with an SD card. The Microsoft Windows System setup disk contains the FDISK and FORMAT utilities as well as the files needed for booting. This disk can be turned into an image file and placed on the SD card to make it bootable.
Download the MS Windows XP System setup disk from here and run it to create a physical floppy disk. Download WinImage from here and use it to create a .vfd file from the floppy. Call the file $tosfd00.vfd. Copy this file to the SD card (and be sure the SD card is formatted for FAT).
The SD card will now boot the laptop just like a floppy. Go ahead and try it out to make sure it works. Once this works, copy the i386 folder from your Windows installation disk to the SD card. If you are installing an OS that requires multiple CDs (such as Windows XP Tablet Edition), be sure to copy the contents of the additional CDs to the SD card now. Your SD card is now bootable and can be used to install Windows.
Copy installation files to the hard disk
Insert the SD card into the laptop and boot up. You should be greeted with a command prompt. Most likely, the current hard disk is formatted in NTFS and will not be read by the boot disk. Type FDISK at the prompt and follow the instructions to view/delete/create partitions as needed. I deleted the existing NTFS partition and created a new one. If you make changes with FDISK, reboot your computer.
Next, type FORMAT followed by the drive letter. The letter of my hard disk was C: so I typed FORMAT C:. Follow the prompts to format your drive. This will format the drive as FAT32. No worries, you’ll convert to NTFS later. Reboot the computer again.
Now the hard disk should be recognized and mounted as C:. Use XCOPY to copy the i386 folder and other supporting files from the SD card to the hard disk. My SD card was mounted as D:, so I typed XCOPY D:\I386 C:\I386 /e /s. This process will take a few minutes. If you copied additional files from multiple install discs, copy these files over as well. I typed XCOPY D:\CMPNENTS C:\CMPNENTS /e /s to copy my additional files.
You are now ready to start the Windows installation. Type SMARTDRV at the prompt. Then change the prompt to your hard disk drive letter by typing C:. Change directories to the i386 folder by typing cd I386. Finally, begin setup by typing WINNT. The installer will copy files and may ask some questions. You’ll probably want to convert the format to NTFS when prompted. If asked for the location of files on disk 2 or 3, browse to the location where you copied those files to the hard disk. Enjoy!
The Toshiba Portege M200 is a total POS. In fact, that whole line of Porteges are POSs. Regardless, should you run into trouble and need to reinstall Windows without an external CD drive or network installation, installing Windows from an SD card is relatively simple and quick once you know what to do. Feel free to comment any good info you’ve discovered or ask questions.