Hi,
If you can access the user account section as administrator, just make new accounts as needed. But it also sounds like you have picked up a virus or malware, don't trust your own virus protection to find all go to:-

http://housecall.trendmicro.com/
or:-
http://security.symantec.com/sscv6/WelcomePage.asp
Download and run to remove any viruses you may have. (Sometimes a virus will stop you accessing an anti-virus site, so try going through safe mode (Tap F8 on boot up) and see if you can access it there.)
Then go to :-
http://www.malwarebytes.org/
or;-
http://majorgeeks.com
Download, then run a “quick check” your PC for any problems, if still there do a “full scan.”

Well ive found the solution (good try MS - but hah!).
ALL the accounts had been locked out?!! (I didnt realsie the graphic login list-view removed a user from the list if locked out, but there you go!)
Reenabled accounts in computer manager view (accounts didnt even exist in 'user accounts control panel icon) and all back to normal.
Question is- WHY did family safety deactivate allaccounts? Am I alone with this problem???
(Antivirus is all activated - pretty sure Im virus free- I jsut let the big ones in = Microsoft!)
thanks for suggestions anyway

Hi,
Glad that everything is OK now, please mark the thread as solved.

PS. It never hurts to be sure and check viruses and malware with another checker.