Step 1:
Check your computer or motherboard manual for any information about upgrading the BIOS.
Step 2:
Reboot your computer and enter the Setup screen. Check your computer or motherboard manual for information on how to do this.
Step 3:
Press the Print Screen key to make a record of each page of your settings.
Step 4:
Find out the manufacturer and model of your current BIOS. Check for the information as your computer boots, or find it in the Setup screen information you printed. If neither method works, check the BIOS chip for identifying information.
Step 5:
Check the manufacturer’s Web site to see if the BIOS can be "flash" upgraded. If so, download the utility program. If not, proceed to Step 8.
Step 6:
Copy the program to a floppy disk.
Step 7:
Follow the manufacturer’s instructions for running the program. Skip to Step 10.
Step 8:
Contact the manufacturer of your BIOS chip to find out if an updated chip is available, and if that chip will fit into the same slot on your motherboard.
Step 9:
Get and install a new BIOS chip, if available. Search the Internet for installation instructions.
Step 10:
Reboot your computer and enter the Setup screen. Change the Setup back to the previous settings if necessary or desired.
Here’s another tutorial, this time about flashing DCT4 Phones using J.A.F.
1. Open J.A.F. software
2. Select the DCT4 tab (it’s selected by default)
3. Click on INF to have JAF read information from your phone such as software version, unlock codes, IMEI along with other information, like this(you can scroll the window for more information):

4. After J.A.F. reads this information from your phone, this isn’t necessary but it’s recommended since you can check the communication is ok, you can proceed to select the files you want to flash into your phone.
5. Click on MCU button and select the corresponding file. If you have correctly installed the flash packages then a window like this should open. In this example the phone is a Nokia 6100.
NEVER DOWNGRADE THE PHONE’S SOFTWARE VERSION!!!! In this case the version is 6.01, so only flash a newer or equal version, otherwise the phone won’t work properly or will die completely.