GWSCAN 5.09 is a diagnostic hard drive utility. This program allows you to verify most hard drives. There are options to check the disk, test the disk, and write zeros to the disk. This GWSCAN version is for IDE hard drives that are larger than 10 gigabytes (GB). If testing or writing zeros to an IDE hard drive that is 10 GB or smaller, GWSCAN version 3.11 is recommended. Note: GWSCAN 5.09 must be run from bootable media because it runs in MS-DOS. Please refer to the Program Use section for instructions on how to run GWSCAN.