Infrared Problem

Whenever I enable the infrared device on my computer, and
then press apply, my computer switches itself off (as
though it had been unplugged) and starts again, but starts
in "Safe Mode". I now cannot seem to rectify the problem -
the computer crashes whenever I try to start it in
the "normal" mode.
Could someone:
1. Tell me how to rectify the problem and start in normal
mode; and
2. Tell me how I could enable my computer's infrared port,
so that I can download some inportant files to it.
Many thanks
Dave