data lifeguard diagnostics for dos iso is here and works with yumi and xboot so far just watch the video
Bootable Flash Drive Instructions for Western Digital Data Lifeguard for DOS
DLG for DOS : http://download.wdc.com/dlg/dlgdiag_5_25.zip
ok … i found a download link to the ISO (Diag504fCD.iso) burnt it on a disc and it works fine
(needless to say, set CDROM as the 1st Boot Device in your PC’s Bios)