Just an update, managed to do a restart before going home last night and all came back to life. I let all the usual backup routines run and remoted in late last night and processed the waiting Windows Updates; again, restart went ok and so far everything seems to be ok.

Most odd. Will keep an eye on things today.

I look at shrinking stuff later on today, do a bit of reading up on it first.

Again, thanks for help and suggestions thus far, as always; appreciated.