Sons laptop been running fine for 5 months + since new.  It's running a Windows 8 factory install.

He powered it up last night, logged into his main account  and the machine then went through the process of setting itself up as if new. Took about 15 minutes to set everything up again.

I think its actually 'refreshed' as there is also a folder of Apps, Games, Virus checkers and various bits and bobs of software it cleaned out.  It went right back to Day 1 state with all the " free for 2 months"  features reloaded onto the machine - Norton etc. 

I had created a recovery disc on an external HDD  but can't seem to boot from it under the advanced startup options so am in process of re-installing for him.

Any clues as to why it did this/ what could cause this or is it simply one of those mysterious Windows 8 things.

Cheers for your thoughts

Ged