Trying to update to OS 1.23

Hey I'm trying to update my MPC 2500 to OS 1.23. I have already dragged the unzipped file to my compact flash card and I have turned off my mpc. When I try to load it back up while holding the window key it says "Wrong Card!!" Why is this

first: try it with the original akai cf card, sometimes the os upgrade won´t work with other cards, even if the card itself works.
second: put the os .bin file to the root directory of the cf card not into a folder.
third: try loading the os through the load page, the mpc should then say something about os upgrade and ask you for permission to do so.
other than that your technique with the window button is the official way and should also work.

peace jo