Done. I have updated to F10 bios, wich also changed GA startup logo screen, but didn't last the 1st turning off/on process. Actually this issue starts when I turn of PC. This time the W7 Login screen booted, but as soon as my password was entered, screen went black for 5min and never started Menu nor desktop icons.
Again, hard reseted, entered Bios, MIT, Memory Freq, moved down from Extreme to Turbo enhance, saved and exit, now I´m posting this reply.
What else can I do??, although im getting tired of this as Im pretty confident it is not my motherboard but all the H55m series.
Thank you.