NtAllocateUserPhysicalPagesEx
Other → NTSTATUS
NtAllocateUserPhysicalPagesEx is a Windows NT kernel system call, in the Other category, returning NTSTATUS. Its syscall number is not the same on every Windows release: across the 18 version-and-architecture pairs recorded here it takes 5 distinct values, from 0x0074 to 0x01B6.
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 (18)
| OS Version | Architecture | Number |
|---|---|---|
| Windows 10 2004 | x64 | 0x0074 (116) |
| Windows 10 2004 | x86 | 0x01B5 (437) |
| Windows 10 20H2 | x86 | 0x01B5 (437) |
| Windows 10 20H2 | x64 | 0x0074 (116) |
| Windows 10 21H1 | x86 | 0x01B5 (437) |
| Windows 10 21H1 | x64 | 0x0074 (116) |
| Windows 10 21H2 | x86 | 0x01B6 (438) |
| Windows 10 21H2 | x64 | 0x0074 (116) |
| Windows 10 22H2 | x86 | 0x01B6 (438) |
| Windows 10 22H2 | x64 | 0x0074 (116) |
| Windows 11 and Server 11 21H2 | x64 | 0x0074 (116) |
| Windows 11 and Server 11 22H2 | x64 | 0x0074 (116) |
| Windows 11 and Server 11 23H2 | x64 | 0x0074 (116) |
| Windows 11 and Server 11 24H2 | x64 | 0x0076 (118) |
| Windows 11 and Server 11 25H2 | x64 | 0x0076 (118) |
| Windows 11 and Server Server 2022 | x64 | 0x0074 (116) |
| Windows 11 and Server Server 2025 | x64 | 0x0076 (118) |
| Windows 11 and Server Server 23H2 | x64 | 0x0075 (117) |