I was able to build my own A12 bios for a Precision M50. This laptop is almost identical to the C840 but has a better video board and a few other quirks so I did not want to use that A13 bios that tqhoang supplied me. There is only an M50_A12.exe bios available (no A13 like the latitude) which I downloaded from Dell and put into "M50" directory. Extracted DELLM09_V2.1.bin from the C840A131_SLIC.EXE that was provided by tqhoang and verified it was byte for byte identical to the Dell[DELL-M09-ASL]2.1.BIN certificate in the SLIC 2.1 BINS repository. Put that bin at "M50\temp" (to prevent it from being deleted by the bios tool) Ran RW everything on my Precision M50 and put AcpiTbls.rw into "M50\temp". I had previously cloned the C840 hard drive for the Precison M50. When I did that, the SLIC ToolKit showed a cert error as there was no table in the bios yet. Ran that 2.11 bios tool with inputs "M50_A12.exe", "DELLM09_V2.1.bin" and the "AcpiTbls.rw". I hit GO and it produced M50_A12_SLIC.exe which installed just fine from a dos boot floppy. After rebooting with the new bios, the SLIC ToolKit no longer showed an error for the cert. [EDIT] Hmm - I tried to add this to the C840 thread but it ended up at the Mods root!