I am frozen in fastboot on the blue screen when I tried to back up my rom. Any help please?
There is no "blue screen" in HBOOT mode, nor in recovery boot, nor in FASTBOOT mode.
Recovery boot - assuming that you have the Amon_RA custom recovery installed, has a black background with an HTC icon, and menus in the form of a green font. You start the recovery boot from a power-off state by pressing and holding both Vol-Up and End/Power until the screen lights up (making sure to press Vol-Up first). You should see 3 (green) skateboarding Droids for 8-10 seconds; afterwards you will see either the Amon_RA recovery menu, or a graphic (usually the graphic contains a triangle and exclamation point, and either an image of the phone or a little green android) if the stock HTC recovery is still on the phone.
The HBOOT screen has a white background with text/lettering of a variety of colors; you start the HBOOT boot from a power-off state by pressing and holding both Vol-Down and End/Power until the screen lights up (making sure to press the Vol-Down key first). You will know it is the HBOOT screen because it says right on it - guess what? - "HBOOT".
The FASTBOOT screen also has a white background with text/lettering of a variety of colors; you start the FASTBOOT boot from a power-off state by pressing and holding both Send and End/Power until the screen lights up (making sure to press the Send key down first). You can get to either the HBOOT mode or even the Recovery boot by choosing the appropriate menu items in this mode.
There is a possibility that you are in Amon_RA and your trackball is not working - but given your description of "blue screen", I don't know where exactly you are. (You are not using ROM Manager/Clockwork are you?)
eu1
PS It is OK to start a new thread, rather than reviving one that is five months old.