I'll have look (once I get the PC back from the rest of my family - so probably tomorrow).
I will probably try switching auto updates off and back on in case the software has - to use a programming term - disappeared up its own arse.
I'll report back....
EDIT (part 1)
Right, checked the update history, the seven updates were all failing to install!
Tried manually updating using the update centre, and all installed successfully except one:
Security update for .NET framework 4
I'll try doing that manually now, and see how I get on....
EDIT (part 2)
Manual update for .NET framework 4 failed too, so did a bit of digging on the error code which was displayed (Code 66A) and some keywords. Got some advice from some helpful geeks. Downloaded and re-installed .NET Framework 4, then applied the update...and voila! Seems to have done the trick.
Thanks for the replies, they put me on the right track!