diff --git a/reactos/include/psdk/aclapi.h b/reactos/include/psdk/aclapi.h
index eff960c6d3b..36bd610a2eb 100644
--- a/reactos/include/psdk/aclapi.h
+++ b/reactos/include/psdk/aclapi.h
@@ -27,7 +27,9 @@ VOID WINAPI BuildTrusteeWithObjectsAndSidA(PTRUSTEE_A,POBJECTS_AND_SID,GUID*,GUI
 VOID WINAPI BuildTrusteeWithObjectsAndSidW(PTRUSTEE_W,POBJECTS_AND_SID,GUID*,GUID*,PSID);
 VOID WINAPI BuildTrusteeWithSidA(PTRUSTEE_A,PSID);
 VOID WINAPI BuildTrusteeWithSidW(PTRUSTEE_W,PSID);
+#if (_WIN32_WINNT >= 0x0501)
 DWORD WINAPI FreeInheritedFromArray(PINHERITED_FROMW,USHORT,PFN_OBJECT_MGR_FUNCTS);
+#endif
 DWORD WINAPI GetAuditedPermissionsFromAclA(PACL,PTRUSTEE_A,PACCESS_MASK,PACCESS_MASK);
 DWORD WINAPI GetAuditedPermissionsFromAclW(PACL,PTRUSTEE_W,PACCESS_MASK,PACCESS_MASK);
 DWORD WINAPI GetEffectiveRightsFromAclA(PACL,PTRUSTEE_A,PACCESS_MASK);
diff --git a/reactos/include/psdk/dsgetdc.h b/reactos/include/psdk/dsgetdc.h
new file mode 100644
index 00000000000..6e147106252
--- /dev/null
+++ b/reactos/include/psdk/dsgetdc.h
@@ -0,0 +1,115 @@
+#ifndef _DSGETDC_H
+#define _DSGETDC_H
+#if __GNUC__ >=3
+#pragma GCC system_header
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define DS_DOMAIN_IN_FOREST       0x01
+#define DS_DOMAIN_DIRECT_OUTBOUND 0x02
+#define DS_DOMAIN_TREE_ROOT       0x04
+#define DS_DOMAIN_PRIMARY         0x08
+#define DS_DOMAIN_NATIVE_MODE     0x10
+#define DS_DOMAIN_DIRECT_INBOUND  0x20
+
+typedef struct _DOMAIN_CONTROLLER_INFOA
+{
+	LPSTR DomainControllerName;
+	LPSTR DomainControllerAddress;
+	ULONG DomainControllerAddressType;
+	GUID DomainGuid;
+	LPSTR DomainName;
+	LPSTR DnsForestName;
+	ULONG Flags;
+	LPSTR DcSiteName;
+	LPSTR ClientSiteName;
+} DOMAIN_CONTROLLER_INFOA, *PDOMAIN_CONTROLLER_INFOA;
+
+typedef struct _DOMAIN_CONTROLLER_INFOW
+{
+	LPWSTR DomainControllerName;
+	LPWSTR DomainControllerAddress;
+	ULONG DomainControllerAddressType;
+	GUID DomainGuid;
+	LPWSTR DomainName;
+	LPWSTR DnsForestName;
+	ULONG Flags;
+	LPWSTR DcSiteName;
+	LPWSTR ClientSiteName;
+} DOMAIN_CONTROLLER_INFOW, *PDOMAIN_CONTROLLER_INFOW;
+
+typedef struct _DS_DOMAIN_TRUSTSA
+{
+	LPSTR NetbiosDomainName;
+	LPSTR DnsDomainName;
+	ULONG Flags;
+	ULONG ParentIndex;
+	ULONG TrustType;
+	ULONG TrustAttributes;
+	PSID DomainSid;
+	GUID DomainGuid;
+} DS_DOMAIN_TRUSTSA, *PDS_DOMAIN_TRUSTSA;
+
+typedef struct _DS_DOMAIN_TRUSTSW
+{
+	LPWSTR NetbiosDomainName;
+	LPWSTR DnsDomainName;
+	ULONG Flags;
+	ULONG ParentIndex;
+	ULONG TrustType;
+	ULONG TrustAttributes;
+	PSID DomainSid;
+	GUID DomainGuid;
+} DS_DOMAIN_TRUSTSW, *PDS_DOMAIN_TRUSTSW;
+
+DWORD
+DsEnumerateDomainTrustsA(
+	LPSTR ServerName,
+	ULONG Flags,
+	PDS_DOMAIN_TRUSTSA* Domains,
+	PULONG DomainCount);
+
+DWORD
+DsEnumerateDomainTrustsW(
+	LPWSTR ServerName,
+	ULONG Flags,
+	PDS_DOMAIN_TRUSTSW* Domains,
+	PULONG DomainCount);
+
+DWORD
+DsGetDcNameA(
+	LPCSTR ComputerName,
+	LPCSTR DomainName,
+	GUID* DomainGuid,
+	LPCSTR SiteName,
+	ULONG Flags,
+	PDOMAIN_CONTROLLER_INFOA* DomainControllerInfo);
+
+DWORD
+DsGetDcNameW(
+	LPCWSTR ComputerName,
+	LPCWSTR DomainName,
+	GUID* DomainGuid,
+	LPCWSTR SiteName,
+	ULONG Flags,
+	PDOMAIN_CONTROLLER_INFOW* DomainControllerInfo);
+
+#ifdef UNICODE
+typedef DOMAIN_CONTROLLER_INFOW DOMAIN_CONTROLLER_INFO, *PDOMAIN_CONTROLLER_INFO;
+typedef DS_DOMAIN_TRUSTSW DS_DOMAIN_TRUSTS, *PDS_DOMAIN_TRUSTS;
+#define DsEnumerateDomainTrusts DsEnumerateDomainTrustsW
+#define DsGetDcName DsGetDcNameW
+#else
+typedef DOMAIN_CONTROLLER_INFOA DOMAIN_CONTROLLER_INFO, *PDOMAIN_CONTROLLER_INFO;
+typedef DS_DOMAIN_TRUSTSA DS_DOMAIN_TRUSTS, *PDS_DOMAIN_TRUSTS;
+#define DsEnumerateDomainTrusts DsEnumerateDomainTrustsA
+#define DsGetDcName DsGetDcNameA
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+#endif
\ No newline at end of file
diff --git a/reactos/include/psdk/winnt.h b/reactos/include/psdk/winnt.h
index eadddf10071..4191eda6b33 100644
--- a/reactos/include/psdk/winnt.h
+++ b/reactos/include/psdk/winnt.h
@@ -2334,6 +2334,8 @@ typedef struct _SID {
    SID_IDENTIFIER_AUTHORITY IdentifierAuthority;
    DWORD SubAuthority[ANYSIZE_ARRAY];
 } SID, *PISID;
+#define SECURITY_MIN_SID_SIZE (sizeof(SID))
+#define SECURITY_MAX_SID_SIZE (FIELD_OFFSET(SID, SubAuthority) + SID_MAX_SUB_AUTHORITIES * sizeof(DWORD))
 typedef struct _SID_AND_ATTRIBUTES {
 	PSID Sid;
 	DWORD Attributes;