If you are looking for verified files, it is recommended to use the official sources to avoid potential malware in unofficial "fixed" versions:
When you finally boot your working copy of Hiren’s 15.4, here is what you unlock: hiren boot cd 154 fixed link
The official MD5 for a 15.4 ISO is: 0f1a962e8c176896f02a562a3c7e84ab (Double-check this hash on the Internet Archive page before trusting) If you are looking for verified files, it
Once you have located a working ISO link, follow these steps to use it: All Hirens BootCD Versions - GitHub Gist Hiren's BootCD 15.2
While there is no official "15.4" release, the community often uses that term to refer to fixed or "Restored" editions of the final official DOS-based release, Hiren's BootCD 15.2