That version 5.50 was used to activate Windows 7. You need to PM snOOze and ask how he Flashed it. I would guess he flashed from DOS with AFUDOS but I'm not 100 % sure on that. FROM the .txt file that came with the original BIOS: this Bios is only for models with Modelnumber PSL48x, PSL49x, PSL4Bx or PSL4Cx