A high integrity storage manager protects critical system files by maintaining a list of protected disk blocks in hardware, such as in a memory of a microcontroller. The memory is inaccessible to software running on a host system comprising the microcontroller. This list of protected disk blocks is protected as “read only” by the hardware so that no write operation issued by software running on the host platform can overwrite a protected disk block. The high integrity storage manager intercepts write operations issued by applications via the operating system and file system running on the host processor and compares the disk blocks targeted by those write operations to the list of protected disk blocks. A write operation that would overwrite a disk block in the list of protected disk blocks is prevented from completion. Other embodiments are described and claimed.