My copy of Windows 8.1.1 x64 works very well, as does my computer in general.

When I restart my computer, it has no video signal for about 60 seconds and then the OEM (Dell) splash screen appears and booting proceeds normally.

I can tell there's no video signal because my monitor displays a message NO HDMI SIGNAL and the power light on the bezel changes from 'on' (white - signal received) to 'standby' (amber - no signal.)

Now I realize that the video connection isn't established instantly on restart. However, in the past my monitor needed only 2-3 seconds to acquire a signal from my video card, and now it takes about 60 seconds. In all other respects, my monitor and video card seem to work flawlessly. Reinstalling the video driver makes no difference.

What could be the cause of this 60-second delay?