Backup of excel - files

I have tested a lot of bacup programs.

The test also includes binary compare of the sourcecfiles and the backup files.

In general there is always a binary difference when comparing excel files with the backup versions, no matter the program used to backup, and i have tried several.

In the start it worried me, but any backed-up versions always worked in excel .

Also,i tested the hd for errors and found no errors.

It seems that excel file "ends" before end actual binary lengt of the file itself.

That have almost never happened with any other files (unless there was an error on the hd, diference in download).