As to why it is taking so long... I have no idea.
But it is better to have it take a minute or two (how long it took on my system... maybe even less) to see what the GPU can do and the resolution of the monitor and all that so that when the user gets into the OS, they are actually greeted by the best looking UI they can handle, at the correct res (this was the first time that upon first boot into Windows, all the display stuff was already taken care of for me)