Thanks Zort for your quick reply. I did flash my Acer M5640 with your BIOS and my Vista did not pass the validation. I did a backup of my flash before the update so I can restore it if I cannot do my Windows 7 upgrade soon. Just a question, I used the Acer tool AFUWIN to flash my BIOS and I saw in the CMOS section that I had 2 choices 'Do nothing' or 'destroy CMOS checksum'. I left it to 'do nothing' as it was the default value but now, when I restart my computer I have a 'CMOS Checksum Bad' error which I can bypass by hitting F2. Shall I reflash my computer with the 'destroy CMOS checksum' selected?