This seems to be asked a lot so here goes:
To upgrade your firmware on the iriver PMP-100 series (PMP-100, PMP-120, PMP-140):
1. download the latest firmware file.
2. Unpack it (usually a zip file)
3. Connect your PMP to your computer.
4. Copy the .tar file (called pmp100.tar or something like that) from the files extracted from the zip file to the root directory on your PMP.
5. On your PMP, go to Setup > System > Firmware Upgrade
6. Select yes, you want to upgrade.
7. Do not touch your PMP until it says you may power off.
8. Reboot.
9. Your PMP may be in a different language when you power on, do not freak out. If so, navigate to Settings again and select the first icon. Hit right a few times and select a different language. Reboot. Repeat until you get english.
Hope this helps.
