Firstly, .bat files are new for me so apologies for my lack of knowledge...
Is there a way that you could have the ''update.bat'' check the amount of files in your ''music'' folder and only run config if the amount is higher?
eg,
IF ''music folder'' is same amount of files as log.txt
THEN
Delete Database Files
ELSE
Exit and load Freebox
I already have a .bat that will count the folders, just need one to compare...
Cheers!