No display on restart.

I was just using my pc when I was prompted that windows updates were ready to be installed in my pc. When I clicked ok and started installation, something seemed to go wrong. Internet connection was removed; printers disappeared; Mcafee antivirus and spybot software did not open when I clicked on their respective icons. Futhermore when I tried to restart my computer, the computer seemed to restart but there was no display. The monitor just displays ‘No signal’. When computer was left switched off for some time and then started display was available. But again if it is restarted immediately there is no display. It has to be left switched off for some time in order for display to work.
I tried repairing XP but the same still happens. System restore did not appear when clicked.
Can you please guide me what to do next?