try this method !!

Dont connect your device unless i tell you to
go to run:
cmd
cd\program files\maemo\flasher-3.5
flasher-3.5 -F (RX.bin) -f -R

wait untill it shows suitable device not found !!

switch of your n900 HOLD U and connect the USB to some NEW USB PORT where it will INSTALL AND DETECT THE N900 AGAIN....

i guess it should work then !!

please REVIEW REVIEW REVIEW the method !! thank you