Overlapped I/O error installing SQL Server 2008 R2 SP2 Express
I eventually located an answer to this. There are multiple steps that you need to perform to ensure that this does not occur, and any one of the items on the list can cause the issue.


If any of these MS patches are installed, delete them. Any one can cause this issue


KB2918614 (The classic cause, but not the cause in this case)
KB3000988
KB3008627
KB3072630

Rename or delete the folder C:\ProgramData\Microsoft\Crypto\RSA\S-1-5-18
Rename or delete the folder C:\Users\[username]\AppData\Microsoft\Crypto\RSA\S-1-5-18


In this particular case, one patch (KB3072630), and the two files all needed to be dealt with to fix the issue - or, to be more precise, I dealt with these three items before the issue was fixed.