I'm having trouble Flashing a Dell Latitude D830 with Bios Version A10 to Bios version A12 when i boot up (via PXE) with a Boot.wim that has the file D830_A12.exe inside it. The error message i receive is : "The AC adapter and battery must be plugged in before the system BIOS can be flashed. Press OK when they are both plugged in or CANCEL to quit."
I dubble checked if the battery and netadapter were properly connected. The same message keeps reappearing over and over again when i press OK. I tried booting up in with Windows Xp SP3 on the same computer and lauching the same file. This action gives no error and the Dell Bios Flash tool offers to upgrade the A10 bios to the A12 bios.
How can i resolve this?

You can't resolve this. Dell has to. It's the way their BIOS flash utility works. It wants to query the power management subsystem to make sure there is A/C power but can't because there isn't one in PE. I have spoke with Dell support about this and their only response is they will be adding the capability to future BIOS updates. The only one I've seen work is for the OptiPlex 755 starting with A08. They told me the desktop and laptop people don't work together so we just have to sit and wait for laptops to start getting PE support. Hopefully the new E-Series will have it.

What i feared for . Maybe it is possible to Filemon regmon what WMI call to the powersubsystem are? Any experience on that?

Try adding the switch "/forceit" (without quotes) to the exe-file in question. It has worked with all the BIOSes I have tried from Dell so far, so I don't see why it shouldn't work with yours. It forces the BIOS to run on systems with no battery and AC adapter attached, but it should not be any danger for you if you have the battery and AC adapter connected

Wow, thanks a ton! I guess I need to figure out how to talk to the right people (or search the right forums) to get the real answers. I used "/forceit /nopause" from a script and it silently set up the flash to perform upon rebooting, which was successful.