The new drive wiper utility does not erase everything on the entire boot drive (the drive which is running the operating system on it). But it will however, wipe everything on partitioned drive(s), flash drives, slave drives, and external drives. A very nice addition to the program. There are other tools/programs out there that will create a boot disk which will wipe your entire main drive securely. It would be nice if ccleaner would include that type of utility in a future version.