Dear colleagues, the linker warning LNK4078 (static builds only) SHOULD NOT be ignored on Win64. The problem is known and is connected to the automatic invocation of OPENSSL_cpuid_setup by placing "dq OPENSSL_cpuid_setup" in the special COFF section CRT$XCU. The problem is that you cannot specify the right COFF section flags for CRT$XCU (using nasm), which SHOULD be 0x40000040 (meaning IMAGE_SCN_MEM_READ and IMAGE_SCN_CNT_INITIALIZED_DATA). I am patching the file x86_64cpuid.obj after nasm has created it to circumvent the problem. If you fail to specify the right section flags here, your entire .rdata section (all CRT$<any>'s are merged into .rdata) may be messed up - under some circumstances, a CPU exception is raised (DEBUG builds) because some parts of the section are filled with the sentinel byte 0xCC! Cheers, Gero.