As I chanced upon this PC during troubleshooting, it was really difficult to update the BIOS because all of Acer's updates were in *.exe and I had no idea how to extract the files using a Resource Hacker! So I decided to scourge Google..
All thanks to http://one-sick-psi-guy.blogspot.com/2009/01/another-bios-update-for-m5640-m3640.html for the fix!
Sneaky Acer released another two BIOS updates for the M5640, with the latest being revision R01-B4 for Windows platforms only and its a large one in comparison with older revisions (over 2MB this time round). I totally missed the B3 revision 'cos I haven't been checking the sites for sometime.
What's changed? No documentation or readme was provided to list down the changes or fixes. The only major thing I notice is that the 'AUTO' option has been removed from the 'Installer OS select' parameter and now only lists 'Windows' or 'Linux'. I wonder if this will affect my attempts later to install MacOS ...
The other thing is the automatic shutdown option upon overheating has been removed from the PC Health Status section. Funny thing about this update is the default settings turn off all the options for wakeup using keyboard/LAN/mouse upon standby but that's easily changed. Anyways, BIOS downloads for these BIOS updates are only found on the European site. Direct links here:
R01-B4 for Windows only (Acer Euro site)
R01-B3 for Linux only(Acer Euro site)
P/S : The colour scheme hasn't changed and remains the same yellow text on blue. The pic above uses the alternative colour scheme obtainable by pressing F3.
UPDATE 5th June 2009!!!
TWO bios releases for Acer Aspire desktop models M5640/M5641/M3640/M1640 to version R01-C2. No noticeable changes to the BIOS in terms of menu options - so this might be a stability fix release (no documentation about features provided in any Acer site).
R01-C2 flashes in Windows using the AFUWIN executable whilst R01-C2L has a larger BIOS binary but only provides the MS-DOS flasher. Both work and don't seem to be any different other than version number ... so download the C2L version for the newer BIOS binary and C2 for the Windows flasher if you're not comfortable flashing with a boot device. Direct links to Acer servers as follows
Download R01-C2 with Windows-based flasher.
Download R01-C2L with CLI based flasher for DOS boot disks.