diff --git a/reactos/base/system/services/config.c b/reactos/base/system/services/config.c
index c3998c34d51..42d5f1bdc79 100644
--- a/reactos/base/system/services/config.c
+++ b/reactos/base/system/services/config.c
@@ -15,6 +15,11 @@
 #define NDEBUG
 #include <debug.h>
 
+ULONG
+NTAPI
+RtlLengthSecurityDescriptor(
+  _In_ PSECURITY_DESCRIPTOR SecurityDescriptor);
+
 /* FUNCTIONS *****************************************************************/
 
 
@@ -504,46 +509,12 @@ ScmWriteSecurityDescriptor(
     _In_ HKEY hServiceKey,
     _In_ PSECURITY_DESCRIPTOR pSecurityDescriptor)
 {
-    PSECURITY_DESCRIPTOR pRelativeSD = NULL;
     HKEY hSecurityKey = NULL;
-    DWORD dwBufferLength = 0;
     DWORD dwDisposition;
     DWORD dwError;
-    NTSTATUS Status;
 
     DPRINT1("ScmWriteSecurityDescriptor(%p %p)\n", hServiceKey, pSecurityDescriptor);
 
-    Status = RtlAbsoluteToSelfRelativeSD(pSecurityDescriptor,
-                                         NULL,
-                                         &dwBufferLength);
-    if (Status != STATUS_BUFFER_TOO_SMALL)
-    {
-DPRINT1("\n");
-        return RtlNtStatusToDosError(Status);
-    }
-
-    DPRINT1("BufferLength %lu\n", dwBufferLength);
-
-    pRelativeSD = RtlAllocateHeap(RtlGetProcessHeap(),
-                                  HEAP_ZERO_MEMORY,
-                                  dwBufferLength);
-    if (pRelativeSD == NULL)
-    {
-DPRINT1("\n");
-        return ERROR_OUTOFMEMORY;
-    }
-
-DPRINT1("\n");
-    Status = RtlAbsoluteToSelfRelativeSD(pSecurityDescriptor,
-                                         pRelativeSD,
-                                         &dwBufferLength);
-    if (!NT_SUCCESS(Status))
-    {
-DPRINT1("\n");
-        dwError = RtlNtStatusToDosError(Status);
-        goto done;
-    }
-
 DPRINT1("\n");
     dwError = RegCreateKeyExW(hServiceKey,
                               L"Security",
@@ -565,17 +536,14 @@ DPRINT1("\n");
                              L"Security",
                              0,
                              REG_BINARY,
-                             (LPBYTE)pRelativeSD,
-                             dwBufferLength);
+                             (LPBYTE)pSecurityDescriptor,
+                             RtlLengthSecurityDescriptor(pSecurityDescriptor));
 DPRINT1("\n");
 
 done:
     if (hSecurityKey != NULL)
         RegCloseKey(hSecurityKey);
 
-    if (pRelativeSD != NULL)
-        RtlFreeHeap(RtlGetProcessHeap(), 0, pRelativeSD);
-
     return dwError;
 }
 
@@ -586,13 +554,10 @@ ScmReadSecurityDescriptor(
     _Out_ PSECURITY_DESCRIPTOR *ppSecurityDescriptor)
 {
     PSECURITY_DESCRIPTOR pRelativeSD = NULL;
-    PSECURITY_DESCRIPTOR pResizedBuffer = NULL;
     HKEY hSecurityKey = NULL;
     DWORD dwBufferLength = 0;
-    DWORD dwAbsoluteSDSize = 0;
     DWORD dwType;
     DWORD dwError;
-    NTSTATUS Status;
 
     DPRINT("ScmReadSecurityDescriptor()\n");
 
@@ -650,36 +615,6 @@ ScmReadSecurityDescriptor(
         goto done;
     }
 
-    Status = RtlSelfRelativeToAbsoluteSD2(pRelativeSD,
-                                          &dwAbsoluteSDSize);
-    if (Status == STATUS_BUFFER_TOO_SMALL)
-    {
-        pResizedBuffer = RtlReAllocateHeap(RtlGetProcessHeap(),
-                                           0,
-                                           pRelativeSD,
-                                           dwAbsoluteSDSize);
-        if (pResizedBuffer == NULL)
-        {
-            dwError = ERROR_OUTOFMEMORY;
-            goto done;
-        }
-
-        pRelativeSD = pResizedBuffer;
-        Status = RtlSelfRelativeToAbsoluteSD2(pRelativeSD,
-                                              &dwAbsoluteSDSize);
-        if (!NT_SUCCESS(Status))
-        {
-            dwError = RtlNtStatusToDosError(Status);
-            goto done;
-        }
-    }
-    else if (!NT_SUCCESS(Status))
-    {
-
-        dwError = RtlNtStatusToDosError(Status);
-        goto done;
-    }
-
     *ppSecurityDescriptor = pRelativeSD;
 
 done:
diff --git a/reactos/base/system/services/security.c b/reactos/base/system/services/security.c
index 810dd4572da..38811f567cc 100644
--- a/reactos/base/system/services/security.c
+++ b/reactos/base/system/services/security.c
@@ -13,7 +13,7 @@
 #define NDEBUG
 #include <debug.h>
 
-PSECURITY_DESCRIPTOR pDefaultServiceSD = NULL;
+PSECURITY_DESCRIPTOR pDefaultServiceSD = NULL; /* Self-relative SD */
 
 static PSID pNullSid = NULL;
 static PSID pLocalSystemSid = NULL;
@@ -110,6 +110,7 @@ ScmCreateDefaultServiceSD(VOID)
     PACL pDacl = NULL;
     PACL pSacl = NULL;
     ULONG ulLength;
+    DWORD dwBufferLength = 0;
     NTSTATUS Status;
     DWORD dwError = ERROR_SUCCESS;
 
@@ -166,14 +167,14 @@ ScmCreateDefaultServiceSD(VOID)
                          FALSE,
                          TRUE);
 
-
+    /* Create the absolute security descriptor */
     pServiceSD = RtlAllocateHeap(RtlGetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(SECURITY_DESCRIPTOR));
     if (pServiceSD == NULL)
     {
         dwError = ERROR_OUTOFMEMORY;
         goto done;
     }
-DPRINT1("pServiceSD %p\n", pServiceSD);
+    DPRINT("pServiceSD %p\n", pServiceSD);
 
     Status = RtlCreateSecurityDescriptor(pServiceSD,
                                          SECURITY_DESCRIPTOR_REVISION);
@@ -221,23 +222,55 @@ DPRINT1("pServiceSD %p\n", pServiceSD);
         goto done;
     }
 
+    /* Convert the absolute SD to a self-relative SD */
+    Status = RtlAbsoluteToSelfRelativeSD(pServiceSD,
+                                         NULL,
+                                         &dwBufferLength);
+    if (Status != STATUS_BUFFER_TOO_SMALL)
+    {
+        dwError = RtlNtStatusToDosError(Status);
+        goto done;
+    }
 
-    pDefaultServiceSD = pServiceSD;
-DPRINT1("pDefaultServiceSD %p\n", pDefaultServiceSD);
+    DPRINT("BufferLength %lu\n", dwBufferLength);
+
+    pDefaultServiceSD = RtlAllocateHeap(RtlGetProcessHeap(),
+                                        HEAP_ZERO_MEMORY,
+                                        dwBufferLength);
+    if (pDefaultServiceSD == NULL)
+    {
+        dwError = ERROR_OUTOFMEMORY;
+        goto done;
+    }
+    DPRINT("pDefaultServiceSD %p\n", pDefaultServiceSD);
+
+    Status = RtlAbsoluteToSelfRelativeSD(pServiceSD,
+                                         pDefaultServiceSD,
+                                         &dwBufferLength);
+    if (!NT_SUCCESS(Status))
+    {
+        dwError = RtlNtStatusToDosError(Status);
+    }
 
 done:
     if (dwError != ERROR_SUCCESS)
     {
-        if (pDacl != NULL)
-            RtlFreeHeap(RtlGetProcessHeap(), 0, pDacl);
-
-        if (pSacl != NULL)
-            RtlFreeHeap(RtlGetProcessHeap(), 0, pSacl);
-
-        if (pServiceSD != NULL)
-            RtlFreeHeap(RtlGetProcessHeap(), 0, pServiceSD);
+        if (pDefaultServiceSD != NULL)
+        {
+            RtlFreeHeap(RtlGetProcessHeap(), 0, pDefaultServiceSD);
+            pDefaultServiceSD = NULL;
+        }
     }
 
+    if (pServiceSD != NULL)
+        RtlFreeHeap(RtlGetProcessHeap(), 0, pServiceSD);
+
+    if (pSacl != NULL)
+        RtlFreeHeap(RtlGetProcessHeap(), 0, pSacl);
+
+    if (pDacl != NULL)
+        RtlFreeHeap(RtlGetProcessHeap(), 0, pDacl);
+
     return dwError;
 }