My Book not backing up .bmp and .prel files

My Book is not backing up .bmp and .prel files. The user manual for My Book does not specify that .bmp and .prel files are NOT backed up. Should My Book back up these files? Are there other file types that My Book does not back up that are not listed in the users manual?

Hi clk4915,

Which WD Software are you using to create the backup?

Hello Alex,

I am using WD Backup Verson 1.9.6731.39035

Hi clk4915,

Maybe you should try contacting WD’s Technical Support about this.

To Contact WD for Technical Support

The link below will allow you to call support.

Thank you for your suggestion.