Would the program only wipe the entire C drive? I do not see a way it could permanently erase only specific files
To only erase for example single files you have to normally delete them so that they're stored in the Recycle Bin. Then when Secure Delete enabled and the Recycle Bin ticked in CCleaner it will secure overwrite what's in the Recycle Bin.
Although it's been a requested feature for many years now for them to have something more user friendly like a drag 'n' drop or right-click ability to secure overwrite individual files or folders.
Drive Wiper will not let you try to entirely wipe the System Drive, usually the C drive, it will only wipe the free space on that drive.
Entirely wiping the System Drive would delete Windows itself.