diff --git a/reactos/win32ss/gdi/eng/device.c b/reactos/win32ss/gdi/eng/device.c
index 32d0ce629fb..d5b65ccff61 100644
--- a/reactos/win32ss/gdi/eng/device.c
+++ b/reactos/win32ss/gdi/eng/device.c
@@ -113,7 +113,8 @@ EngpRegisterGraphicsDevice(
     pGraphicsDevice->pwszDescription = pwsz + pustrDiplayDrivers->Length / sizeof(WCHAR);
     RtlCopyMemory(pGraphicsDevice->pwszDescription,
                   pustrDescription->Buffer,
-                  pustrDescription->Length + sizeof(WCHAR));
+                  pustrDescription->Length);
+    pGraphicsDevice->pwszDescription[pustrDescription->Length/sizeof(WCHAR)] = 0;
 
     /* Initialize the pdevmodeInfo list and default index  */
     pGraphicsDevice->pdevmodeInfo = NULL;
diff --git a/reactos/win32ss/user/ntuser/misc/registry.c b/reactos/win32ss/user/ntuser/misc/registry.c
index 81dff489ebf..9258027299d 100644
--- a/reactos/win32ss/user/ntuser/misc/registry.c
+++ b/reactos/win32ss/user/ntuser/misc/registry.c
@@ -58,7 +58,7 @@ RegQueryValue(
     ULONG cbInfoSize, cbDataSize;
 
     /* Check if the local buffer is sufficient */
-    cbInfoSize = FIELD_OFFSET(KEY_VALUE_PARTIAL_INFORMATION, Data) + *pcbValue;
+    cbInfoSize = FIELD_OFFSET(KEY_VALUE_PARTIAL_INFORMATION, Data[*pcbValue]);
     if (cbInfoSize <= sizeof(ajBuffer))
     {
         pInfo = (PVOID)ajBuffer;
@@ -82,7 +82,7 @@ RegQueryValue(
                              cbInfoSize,
                              &cbInfoSize);
 
-    cbDataSize = cbInfoSize - FIELD_OFFSET(KEY_VALUE_PARTIAL_INFORMATION, Data);
+    cbDataSize = pInfo->DataLength;
 
     /* Note: STATUS_BUFFER_OVERFLOW is not a success */
     if (NT_SUCCESS(Status))