diff --git a/reactos/dll/win32/lsasrv/database.c b/reactos/dll/win32/lsasrv/database.c
index c7b770c7131..faa85ba65a8 100644
--- a/reactos/dll/win32/lsasrv/database.c
+++ b/reactos/dll/win32/lsasrv/database.c
@@ -199,12 +199,42 @@ Done:
 }
 
 
+static NTSTATUS
+LsapCreateRandomDomainSid(OUT PSID *Sid)
+{
+    SID_IDENTIFIER_AUTHORITY SystemAuthority = {SECURITY_NT_AUTHORITY};
+    LARGE_INTEGER SystemTime;
+    PULONG Seed;
+
+    NtQuerySystemTime(&SystemTime);
+    Seed = &SystemTime.u.LowPart;
+
+    return RtlAllocateAndInitializeSid(&SystemAuthority,
+                                       4,
+                                       SECURITY_NT_NON_UNIQUE,
+                                       RtlUniform(Seed),
+                                       RtlUniform(Seed),
+                                       RtlUniform(Seed),
+                                       SECURITY_NULL_RID,
+                                       SECURITY_NULL_RID,
+                                       SECURITY_NULL_RID,
+                                       SECURITY_NULL_RID,
+                                       Sid);
+}
+
+
 static NTSTATUS
 LsapCreateDatabaseObjects(VOID)
 {
-    PLSA_DB_OBJECT PolicyObject;
+    PLSA_DB_OBJECT PolicyObject = NULL;
+    PSID AccountDomainSid = NULL;
     NTSTATUS Status;
 
+    /* Create a random domain SID */
+    Status = LsapCreateRandomDomainSid(&AccountDomainSid);
+    if (!NT_SUCCESS(Status))
+        return Status;
+
     /* Open the 'Policy' object */
     Status = LsapOpenDbObject(NULL,
                               L"Policy",
@@ -212,7 +242,7 @@ LsapCreateDatabaseObjects(VOID)
                               0,
                               &PolicyObject);
     if (!NT_SUCCESS(Status))
-        return Status;
+        goto done;
 
     LsapSetObjectAttribute(PolicyObject,
                            L"PolPrDmN",
@@ -231,13 +261,17 @@ LsapCreateDatabaseObjects(VOID)
 
     LsapSetObjectAttribute(PolicyObject,
                            L"PolAcDmS",
-                           NULL,
-                           0);
+                           AccountDomainSid,
+                           RtlLengthSid(AccountDomainSid));
 
-    /* Close the 'Policy' object */
-    LsapCloseDbObject(PolicyObject);
+done:
+    if (PolicyObject != NULL)
+        LsapCloseDbObject(PolicyObject);
 
-    return STATUS_SUCCESS;
+    if (AccountDomainSid != NULL)
+        RtlFreeSid(AccountDomainSid);
+
+    return Status;
 }
 
 
diff --git a/reactos/dll/win32/lsasrv/lsasrv.h b/reactos/dll/win32/lsasrv/lsasrv.h
index 79f7ed49937..7442977e371 100644
--- a/reactos/dll/win32/lsasrv/lsasrv.h
+++ b/reactos/dll/win32/lsasrv/lsasrv.h
@@ -11,6 +11,7 @@
 #include <windows.h>
 #define NTOS_MODE_USER
 #include <ndk/cmfuncs.h>
+#include <ndk/kefuncs.h>
 #include <ndk/lpctypes.h>
 #include <ndk/lpcfuncs.h>
 #include <ndk/obfuncs.h>
diff --git a/reactos/dll/win32/syssetup/globals.h b/reactos/dll/win32/syssetup/globals.h
index 385b5c810c4..483a6d4d7f5 100644
--- a/reactos/dll/win32/syssetup/globals.h
+++ b/reactos/dll/win32/syssetup/globals.h
@@ -64,6 +64,7 @@ extern SETUPDATA SetupData;
 /* security.c */
 NTSTATUS SetAccountDomain(LPCWSTR DomainName,
                           PSID DomainSid);
+NTSTATUS GetAccountDomainInfo(PPOLICY_ACCOUNT_DOMAIN_INFO *AccountDomainInfo);
 VOID InstallSecurity(VOID);
 
 /* wizard.c */
diff --git a/reactos/dll/win32/syssetup/install.c b/reactos/dll/win32/syssetup/install.c
index 1e611254a5a..01b99dde738 100644
--- a/reactos/dll/win32/syssetup/install.c
+++ b/reactos/dll/win32/syssetup/install.c
@@ -36,9 +36,6 @@ CMP_WaitNoPendingInstallEvents(DWORD dwTimeout);
 
 /* GLOBALS ******************************************************************/
 
-PSID DomainSid = NULL;
-PSID AdminSid = NULL;
-
 HINF hSysSetupInf = INVALID_HANDLE_VALUE;
 
 /* FUNCTIONS ****************************************************************/
@@ -227,33 +224,6 @@ CreateShortcutFolder(int csidl, UINT nID, LPTSTR pszName, int cchNameLen)
     return CreateDirectory(szPath, NULL) || GetLastError()==ERROR_ALREADY_EXISTS;
 }
 
-static BOOL
-CreateRandomSid(
-    OUT PSID *Sid)
-{
-    SID_IDENTIFIER_AUTHORITY SystemAuthority = {SECURITY_NT_AUTHORITY};
-    LARGE_INTEGER SystemTime;
-    PULONG Seed;
-    NTSTATUS Status;
-
-    NtQuerySystemTime(&SystemTime);
-    Seed = &SystemTime.u.LowPart;
-
-    Status = RtlAllocateAndInitializeSid(
-        &SystemAuthority,
-        4,
-        SECURITY_NT_NON_UNIQUE,
-        RtlUniform(Seed),
-        RtlUniform(Seed),
-        RtlUniform(Seed),
-        SECURITY_NULL_RID,
-        SECURITY_NULL_RID,
-        SECURITY_NULL_RID,
-        SECURITY_NULL_RID,
-        Sid);
-    return NT_SUCCESS(Status);
-}
-
 static VOID
 AppendRidToSid(
     OUT PSID *Dst,
@@ -878,6 +848,8 @@ SetSetupType(DWORD dwSetupType)
 DWORD WINAPI
 InstallReactOS(HINSTANCE hInstance)
 {
+    PPOLICY_ACCOUNT_DOMAIN_INFO AccountDomainInfo = NULL;
+    PSID AdminSid = NULL;
     TCHAR szBuffer[MAX_PATH];
     DWORD LastError;
     HANDLE token;
@@ -893,23 +865,17 @@ InstallReactOS(HINSTANCE hInstance)
         return 0;
     }
 
-    /* Create the semi-random Domain-SID */
-    if (!CreateRandomSid(&DomainSid))
+    /* Get account domain information */
+    if (GetAccountDomainInfo(&AccountDomainInfo) != STATUS_SUCCESS)
     {
-        FatalError("Domain-SID creation failed!");
-        return 0;
-    }
-
-    /* Set the Domain SID (aka Computer SID) */
-    if (SetAccountDomain(NULL, DomainSid) != STATUS_SUCCESS)
-    {
-        FatalError("SetAccountDomain() failed!");
-        RtlFreeSid(DomainSid);
+        FatalError("GetAccountDomainInfo() failed!");
         return 0;
     }
 
     /* Append the Admin-RID */
-    AppendRidToSid(&AdminSid, DomainSid, DOMAIN_USER_RID_ADMIN);
+    AppendRidToSid(&AdminSid, AccountDomainInfo->DomainSid, DOMAIN_USER_RID_ADMIN);
+
+    LsaFreeMemory(AccountDomainInfo);
 
     CreateTempDir(L"TEMP");
     CreateTempDir(L"TMP");
@@ -964,13 +930,11 @@ InstallReactOS(HINSTANCE hInstance)
         {
             FatalError("SamCreateUser() failed!");
             RtlFreeSid(AdminSid);
-            RtlFreeSid(DomainSid);
             return 0;
         }
     }
 
     RtlFreeSid(AdminSid);
-    RtlFreeSid(DomainSid);
 
     if (!CreateShortcuts())
     {
diff --git a/reactos/dll/win32/syssetup/security.c b/reactos/dll/win32/syssetup/security.c
index ecf892d8666..3d822fb9daf 100644
--- a/reactos/dll/win32/syssetup/security.c
+++ b/reactos/dll/win32/syssetup/security.c
@@ -26,6 +26,8 @@ SetAccountDomain(LPCWSTR DomainName,
     LSA_HANDLE PolicyHandle;
     NTSTATUS Status;
 
+    DPRINT1("SYSSETUP: SetAccountDomain\n");
+
     memset(&ObjectAttributes, 0, sizeof(LSA_OBJECT_ATTRIBUTES));
     ObjectAttributes.Length = sizeof(LSA_OBJECT_ATTRIBUTES);
 
@@ -87,6 +89,38 @@ SetAccountDomain(LPCWSTR DomainName,
 }
 
 
+NTSTATUS
+GetAccountDomainInfo(PPOLICY_ACCOUNT_DOMAIN_INFO *AccountDomainInfo)
+{
+    LSA_OBJECT_ATTRIBUTES ObjectAttributes;
+    LSA_HANDLE PolicyHandle;
+    NTSTATUS Status;
+
+    DPRINT1("SYSSETUP: GetAccountDomain\n");
+
+    memset(&ObjectAttributes, 0, sizeof(LSA_OBJECT_ATTRIBUTES));
+    ObjectAttributes.Length = sizeof(LSA_OBJECT_ATTRIBUTES);
+
+    Status = LsaOpenPolicy(NULL,
+                           &ObjectAttributes,
+                           POLICY_TRUST_ADMIN,
+                           &PolicyHandle);
+    if (Status != STATUS_SUCCESS)
+    {
+        DPRINT("LsaOpenPolicy failed (Status: 0x%08lx)\n", Status);
+        return Status;
+    }
+
+    Status = LsaQueryInformationPolicy(PolicyHandle,
+                                       PolicyAccountDomainInformation,
+                                       (PVOID *)AccountDomainInfo);
+
+    LsaClose(PolicyHandle);
+
+    return Status;
+}
+
+
 static
 VOID
 InstallBuiltinAccounts(VOID)