After a problem with HDD SSD 8Gb it had to be changed to a new one, the Windows was instaled by a external DVD drive! He only boot if he check before if have a boot from external dvd. ===== SOLUTION ====== Get a pen drive less than 2Gb and use a program called PeToUSB and format your pen drive in FAT16 “ATENTION!! FAT is not the same as FAT16″ after download a bios firmware called 900-ASUS-1004.ROM rename it to 900.ROM and copy to your pen drive, put on your netbook and power on, quickly press ALT+F2 and wait… the magic will happend! any question ask me! bye bye
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EEE PC 900 XP Boot Problem (fixed read description)