I have a Excel VBA program that requires around 10 hours of run time.
It accesses multiple files and extracts data. I would like to lock my
PC while the PC is running. The program runs fine as long as I don't
lock (ctrl-alt-del-enter) the PC. I've tried inserting the
LockWorkStation function (see below) in various spots in my code which
does lock the PC but the program still stops running.

Private Declare Function LockWorkStation Lib "user32.dll" () As Long

Does VBA only run on an unlocked PC?