Will all files be deleted if wizard is told to use all of the hard drive?

I want to install Ubuntu on my laptop and I want to let it use all the hard drive so that it could delete my former OS, but I have a large file on my C drive which is the only drive.

I am wondering if the file will stay or will it be deleted when I ask the wizard to use all of the hard drive.

Yes, it will.

• pick "replace windows" at the installer and -anything- related to Windows will get deleted.

If you need a partition that remains as is use a tool in Windows (gparted) to shrink a partition and pick the "something else" option in the installer and then use the unallocated space to install Ubuntu.

But... you start with making a backup.

Yes, it will be deleted. If you intend on erasing Windows when installing Ubuntu, use a flash drive, SD card, Google Drive, Dropbox, etc. to make backups of all your important files.