NtAllocateVirtualMemoryEx
Memory → NTSTATUS
NtAllocateVirtualMemoryEx is a Windows NT kernel system call, in the Memory category, returning NTSTATUS. Its syscall number is not the same on every Windows release: across the 26 version-and-architecture pairs recorded here it takes 7 distinct values, from 0x0074 to 0x01CF.
The number is an index into the system service table of one particular build, not a stable identifier, so it is not portable between Windows versions or between x64 and x86. The table below gives the value recorded for each.
Numbers across OS versions (26)
| OS Version | Architecture | Number |
|---|---|---|
| Windows 10 1803 | x64 | 0x0074 (116) |
| Windows 10 1803 | x86 | 0x01CC (460) |
| Windows 10 1809 | x86 | 0x01CC (460) |
| Windows 10 1809 | x64 | 0x0074 (116) |
| Windows 10 1903 | x86 | 0x01CC (460) |
| Windows 10 1903 | x64 | 0x0074 (116) |
| Windows 10 1909 | x64 | 0x0074 (116) |
| Windows 10 1909 | x86 | 0x01CC (460) |
| Windows 10 2004 | x64 | 0x0076 (118) |
| Windows 10 2004 | x86 | 0x01CE (462) |
| Windows 10 20H2 | x86 | 0x01CE (462) |
| Windows 10 20H2 | x64 | 0x0076 (118) |
| Windows 10 21H1 | x86 | 0x01CE (462) |
| Windows 10 21H1 | x64 | 0x0076 (118) |
| Windows 10 21H2 | x86 | 0x01CF (463) |
| Windows 10 21H2 | x64 | 0x0076 (118) |
| Windows 10 22H2 | x86 | 0x01CF (463) |
| Windows 10 22H2 | x64 | 0x0076 (118) |
| Windows 11 and Server 11 21H2 | x64 | 0x0076 (118) |
| Windows 11 and Server 11 22H2 | x64 | 0x0076 (118) |
| Windows 11 and Server 11 23H2 | x64 | 0x0076 (118) |
| Windows 11 and Server 11 24H2 | x64 | 0x0078 (120) |
| Windows 11 and Server 11 25H2 | x64 | 0x0078 (120) |
| Windows 11 and Server Server 2022 | x64 | 0x0076 (118) |
| Windows 11 and Server Server 2025 | x64 | 0x0078 (120) |
| Windows 11 and Server Server 23H2 | x64 | 0x0077 (119) |