Thanks for the replies guys - prompt as ever
Had a look at the settings and the auto update was set for 3.00am which is odd because we never leave the PC on overnight and it has been updating automatically prior to now
Maybe something happened via an earlier recent update so I've altered the auto update time to 10am every day and will see what happens.
I checked for updates manually and found 2 which I installed a few minutes ago and will report back if I have any further issues.
TVM