Windows Update rebooted my laptop (Win7 Home Premium; 32-bit; Dell Vostro 3500) last night after "successfully completing" several updates. Now I cannot login because the login prompt never appears. Black screen "Starting Windows" swirl completes; goes to blue desktop with Windows 7 Home Premium label at bottom and Ease of Access keyboard icon in top left. Mouse pointer is functional. Keyboard is responsive but no interaction with onscreen items. Every 15 seconds or so, the screen very briefly blinks with a Win7 busy mouse pointer. This just continues. Ctrl-Alt-Del does nothing but I can shut down by pressing the power button briefly.
Rebooting in Safe Mode (with or without Command Prompt) does the same; still no login prompt.
"Last known good" does not appear as an option.
Laptop's recovery partition is not present due to a HDD swap last year (my Acronis disk image included only OS partition - my bad!)
Any suggestions beside booting with a live CD, recoverying data and replacing with old disk image?