Yes, I did wonder saundthorp! 

Wonder what caused it.  I'm thinking of taking a software course myself - at least about trying to understand computer operating systems better than I do.  So I can keep my computer lean and clean and fast. 

Do you know if the problem was software or hardware or just a puzzle?

Morning JJ,
The error message I received says "the problem could be recently installed hardware"
The only hardware I had attached last night was a memory stick I was using to reload my documents folder. I had finished using it but had left it plugged in and was resetting one of my usual web sites, BBC weather when, blatt, the screen went blank and the error message came up.
I followed the instruction for starting up again, ie,
"Start computer using previously known good setting"
"Let computer start normally" etc, but the computer just wouldn't load up and kept going round in circles.
I shut the computer down and even removed the power connector and left it alone for 30 minutes, removed the memory stick and powered up again. Everything came back without a problem.
Last week I took it to my computer man and had XP reinstalled but the problem I had last night was what was happening previously.
Me no understand