I'll try and help.
Yesterday I successfully managed to Flash my Toshiba SD-C2402 drive with Firmware 1317.
I'm very new to this but read a lot of messages before I started then I gave it a go. I will try and detail what I did as it may help you, however like I said i'm new to this so please only use this as advise.
First download DriveInfo v2.1. This will tell you what drive you have as well as the firmware number you require.
http://www.justcdr.v21net.co.uk/dvdtool ... info21.exe
Next download your firmware from the following site.
I've noticed that you said you have a Toshiba SD-C2502 1915. Double check DriveInfo and if this is true then use the following link to download your flash file. However check the .txt file in the .zip. This is confirm the right file.
http://perso.club-internet.fr/farzeno/d ... 2_1915.zip
Then download a plain Windows ME bootdisk. This disk will allow you boot up your PC straight into DOS mode. I use Windows 2000 but this disk still works and got me to my DOS prompt. Use this link to start an automatic download:
http://www.putergeek.com/downloads/popu ... _plain.htm
Next download IDEDIAG from the following website. This application will tell you where your DVD drive is located inside your system. However don't run this in Windows.
Once you have got this far make your ME Bootdisk and also copy the Flash files and IDEDIAG files to the same disk.
Now boot up your system using the boot disk. Once at the DOS prompt run the IDEDIAG program. This will tell you where your DVD drive is situated.
This is where I'm not 100% certain, as I couldn't find much information in the forum. However from what I could see you need to have your DVD drive set as the Secondary Master. Please email a moderator to check this.
If your drive is the Secondary Master then exit the program and run the flash command. This should start and eventually come back to the DOS prompt. It may ask you if you are sure. Once back at the DOS prompt eject the disk and reboot your machine.
Now that you're back in Windows run DriveInfo. Hopefully this should read region free.
IMPORTANT: If you have RegionKiller enabled on your computer disable it before running DriveInfo.
If everything is ok and you don't have RegionKiller then download it from the following website:
http://home.t-online.de/home/CloneCD/do ... egKill.exe
REMEMBER: Yesterday was my first experience with all of this however I read through loads of articles and then ran through the above process myself and now I have a region free Toshiba DVD drive.