you need this software,
download it here.
then type the password to open
remove sim card from phone
connect usb cable, the one that came with your phone.
goto "Set write settings"
select the type of phone you have.
that being "SGH-E900"
then set the port number your phone is on.
this can be found by doing the following;
right click on the my computer icon.
then select hardware.
scroll through until you see ports
left click on this
you will see i description of the phone and the port number it is working on.
samsung SGH-E900(port 6)
close the hardware profiles and then select the port number as detailed
press the ok putton.
scroll down and you will see an icon that is now highlighted saying Unlock.
left click on it.
the screen will go green and say passed.
Samsung SGH-E900 now unlocked.
WARNING DO NOT USE ANY OF THE OTHER FUNCTIONS TO THIS SOFTWARE.
I HAVE TRIED THIS SOFTWARE AS "WORKING" AND WILL NOT BE HELD RESPONSIBLE FOR ANY DAMAGE CAUSED.