XPS 8700 - Black screen before getting to Windows 7 screen. Help plz.

Hello. I recently purchased XPS 8700, replaced the PSU 550W and the video card with MSI GTX 660.

The problem I'm having is the boot up takes too long, almost 2 minutes. I see the black screen for about 1 minute before it proceeds to the window 7 screen.

I updated the vga driver to the latest and others through dell system detect as well.