Can not restart Windows after install

Tonight I bought NIS2009 and installed it on my laptop. No problems. Smooth as silk.

 

Then I went to my desktop. The installation seemed to go well but during the activation phase my desktop just rebooted and now everytime I log in, I get the Windows Startup tune and it reboots before anything can be done. It does start up in Safe Mode.

 

How can I find out what is conflicting with NIS2009?

 

Many thanks in advance.