diff --git a/reactos/dll/directx/dmusic/collection.c b/reactos/dll/directx/dmusic/collection.c
index 06ec6513067..8c9f2aab156 100644
--- a/reactos/dll/directx/dmusic/collection.c
+++ b/reactos/dll/directx/dmusic/collection.c
@@ -209,8 +209,8 @@ static HRESULT WINAPI IDirectMusicCollectionImpl_IDirectMusicObject_SetDescripto
 	if (pDesc->dwValidData & DMUS_OBJ_DATE)
 		This->pDesc->ftDate = pDesc->ftDate;
 	if (pDesc->dwValidData & DMUS_OBJ_MEMORY) {
-		memcpy (&This->pDesc->llMemLength, &pDesc->llMemLength, sizeof (pDesc->llMemLength));				
-		memcpy (This->pDesc->pbMemData, pDesc->pbMemData, sizeof (pDesc->pbMemData));
+		This->pDesc->llMemLength = pDesc->llMemLength;
+		memcpy (This->pDesc->pbMemData, pDesc->pbMemData, pDesc->llMemLength);
 	}
 	if (pDesc->dwValidData & DMUS_OBJ_STREAM) {
 		/* according to MSDN, we copy the stream */
diff --git a/reactos/drivers/filters/mountmgr/mountmgr.c b/reactos/drivers/filters/mountmgr/mountmgr.c
index 260852eb031..229a00a28de 100644
--- a/reactos/drivers/filters/mountmgr/mountmgr.c
+++ b/reactos/drivers/filters/mountmgr/mountmgr.c
@@ -38,7 +38,7 @@ PDEVICE_OBJECT gdeviceObject;
 KEVENT UnloadEvent;
 LONG Unloading;
 
-PWSTR Cunc = L"\\??\\C:";
+static const WCHAR Cunc[] = L"\\??\\C:";
 
 /*
  * TODO:
diff --git a/reactos/drivers/network/ndis/ndis/misc.c b/reactos/drivers/network/ndis/ndis/misc.c
index dca3726dcba..fda3c4bb4b1 100644
--- a/reactos/drivers/network/ndis/ndis/misc.c
+++ b/reactos/drivers/network/ndis/ndis/misc.c
@@ -139,7 +139,7 @@ NDIS_POBJECT_TO_HANDLE ( PNDIS_HANDLE_OBJECT obj )
   return (NDIS_HANDLE)obj;
 }
 
-const WCHAR* NDIS_FILE_FOLDER = L"\\SystemRoot\\System32\\Drivers\\";
+static const WCHAR NDIS_FILE_FOLDER[] = L"\\SystemRoot\\System32\\Drivers\\";
 
 /*
  * @implemented
@@ -242,8 +242,8 @@ NdisOpenFile(
   *Status = NDIS_STATUS_SUCCESS;
   FullFileName.Buffer = NULL;
 
-  FullFileName.Length = sizeof(NDIS_FILE_FOLDER);
-  FullFileName.MaximumLength = FileName->MaximumLength + sizeof(NDIS_FILE_FOLDER);
+  FullFileName.Length = sizeof(NDIS_FILE_FOLDER) - sizeof(UNICODE_NULL);
+  FullFileName.MaximumLength = FileName->MaximumLength + FullFileName.Length;
   FullFileName.Buffer = ExAllocatePool ( NonPagedPool, FullFileName.MaximumLength );
 
   if ( !FullFileName.Buffer )
diff --git a/reactos/lib/sdk/crt/locale/locale.c b/reactos/lib/sdk/crt/locale/locale.c
index 6b7c9da7cd9..5abee62e696 100644
--- a/reactos/lib/sdk/crt/locale/locale.c
+++ b/reactos/lib/sdk/crt/locale/locale.c
@@ -74,8 +74,8 @@ typedef struct {
   LANGID found_lang_id;
 } locale_search_t;
 
-unsigned int __setlc_active;
-unsigned int __unguarded_readlc_active;
+extern unsigned int __setlc_active;
+extern unsigned int __unguarded_readlc_active;
 int _current_category;	/* used by setlocale */
 const char *_current_locale;