Noted, thanks.

I've now found another setuperr.log file - it's a cumulative log so has entries dating back a few years. The most recent entries (for yesterday) are as follows:

2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\$WINDOWS.~Q\*]; GLE = 0x3[gle=0x00000003]
2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\$WINDOWS.~Q\*]; GLE = 0x3[gle=0x00000003]
2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\$INPLACE.~TR\*]; GLE = 0x3[gle=0x00000003]
2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\$INPLACE.~TR\*]; GLE = 0x3[gle=0x00000003]
2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\$Windows.~LS\*]; GLE = 0x3[gle=0x00000003]
2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\$Windows.~LS\*]; GLE = 0x3[gle=0x00000003]
2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\ESD\Download\*]; GLE = 0x3[gle=0x00000003]
2023-04-02 09:14:24, Error EnumeratePathEx: FindFirstFile failed for [C:\ESD\Download\*]; GLE = 0x3[gle=0x00000003]'


Two points to note though, I didn't attempt to run Windows Update then (maybe it was automatic?) or run SetupDiag. I did though try later in the day yet there's no entries in setuperr.log relevant to those times.