I tried to update my HDD firmwareto version CC3D ( Maxtor diamondmax 23 500gb STM3500418AS ) .
Using this update ( http://seagate.custkb.com/seagate/crm/selfservice/searc... ) in the middle of the update my computer freezed, after waiting for half an hour i decided to restart my computer. After that it would not find the HDD. After multiple restarts it found the HDD and now it sometimes boots up and sometimes not, is there a way to get the old firmware back or fixing this problem?
Try downloading and burning the bootable CD image about 1/2-way down the link you posted. Burn it to a CD, then set your optical drive as the first boot device in BIOS - this should cause the system to POST, and then boot to the CD. Let it run, and follow any instructions that appear on the screen during the update - do not turn off the power until it is complete.