FOLLOWED THESE EXACT INSTRUCTIONS THIS MORNING AND HAD 100% SUCCESS. Remember to run BACKUP on your phone first as you will need it after you reboot with the new software.

Following instructions from here: http://wiki.maemo.org/Updating_the_f...ndows_7_32-bit

Flashing using the command line

In order to flash directly from the XP/Vista/Windows 7 command line, follow these steps:

1. Download and install the latest version of Flasher e.g. maemo_flasher-3.5_2.5.2.2.exe
2. Download the latest firmware (.bin) file and save it to %ProgramFiles%\maemo\flasher-3.5\ (the default installation path for Flasher) or to the custom path of your choice.
3. Ensure the battery is at least half full.
4. Unplug charger cable and switch off the device.
5. Open the Command Prompt (Start then Run or Windows Logo key + R) and type cmd then press Enter.
6. Change the directory to the Flasher's path (TIP: Use the TAB key to auto-complete the commands and file-names)

cd "%ProgramFiles%\maemo\flasher-3.5"

7. Hold the u key on the device keyboard and connect the USB cable at the same time (see the Flasher documentation)
8. Run the following command:

flasher-3.5.exe -F RX-51_2009SE_2.2009.51-1_PR_COMBINED_MR0_ARM.bin -f -R

Replace RX-51_2009SE_2.2009.51-1_PR_COMBINED_MR0_ARM.bin with the firmware you wish to update (The name of the firmware image file you downloaded in the beginning).

The update will take approximately 4 minutes after which the N900 will reboot and display the Welcome Screen with Regional settings.