diff --git a/ctypes_generation/definitions/structures/winstruct_alpc.txt b/ctypes_generation/definitions/structures/winstruct_alpc.txt
deleted file mode 100644
index f6862f2..0000000
--- a/ctypes_generation/definitions/structures/winstruct_alpc.txt
+++ /dev/null
@@ -1,276 +0,0 @@
-
-typedef enum _ALPC_PORT_INFORMATION_CLASS
-{
-    AlpcBasicInformation,
-    AlpcPortInformation,
-    AlpcAssociateCompletionPortInformation,
-    AlpcConnectedSIDInformation,
-    AlpcServerInformation,
-    AlpcMessageZoneInformation,
-    AlpcRegisterCompletionListInformation,
-    AlpcUnregisterCompletionListInformation,
-    AlpcAdjustCompletionListConcurrencyCountInformation,
-    AlpcRegisterCallbackInformation,
-    AlpcCompletionListRundownInformation,
-    AlpcWaitForPortReferences,
-    MaxAlpcPortInfoClass
-} ALPC_PORT_INFORMATION_CLASS;
-
-typedef enum _ALPC_MESSAGE_INFORMATION_CLASS
-{
-    AlpcMessageSidInformation,
-    AlpcMessageTokenModifiedIdInformation,
-    MaxAlpcMessageInfoClass,
-    AlpcMessageHandleInformation,
-} ALPC_MESSAGE_INFORMATION_CLASS, *PALPC_MESSAGE_INFORMATION_CLASS;
-
-typedef struct _ALPC_PORT_ATTRIBUTES32
-{
-    ULONG Flags;
-    SECURITY_QUALITY_OF_SERVICE SecurityQos;
-    SIZE_T MaxMessageLength;
-    SIZE_T MemoryBandwidth;
-    SIZE_T MaxPoolUsage;
-    SIZE_T MaxSectionSize;
-    SIZE_T MaxViewSize;
-    SIZE_T MaxTotalSectionSize;
-    ULONG DupObjectTypes;
-} ALPC_PORT_ATTRIBUTES32, *PALPC_PORT_ATTRIBUTES32;
-
-
-typedef struct _ALPC_PORT_ATTRIBUTES64
-{
-    ULONG Flags;
-    SECURITY_QUALITY_OF_SERVICE SecurityQos;
-    SIZE_T MaxMessageLength;
-    SIZE_T MemoryBandwidth;
-    SIZE_T MaxPoolUsage;
-    SIZE_T MaxSectionSize;
-    SIZE_T MaxViewSize;
-    SIZE_T MaxTotalSectionSize;
-    ULONG DupObjectTypes;
-    ULONG Reserved;
-} ALPC_PORT_ATTRIBUTES64, *PALPC_PORT_ATTRIBUTES64;
-
-typedef struct _ALPC_MESSAGE_ATTRIBUTES
-{
-    ULONG AllocatedAttributes;
-    ULONG ValidAttributes;
-} ALPC_MESSAGE_ATTRIBUTES, *PALPC_MESSAGE_ATTRIBUTES;
-
-
-typedef union _PORT_MESSAGE32_TMP_UNION
-{
-        ULONG ClientViewSize;
-        ULONG CallbackId;
-} PORT_MESSAGE_TMP_UNION;
-
-typedef union _PORT_MESSAGE64_TMP_UNION
-{
-        ULONGLONG ClientViewSize;
-        ULONG CallbackId;
-} PORT_MESSAGE_TMP_UNION;
-
-
-typedef struct _PORT_MESSAGE_TMP_SUBSTRUCT_S1
-{
-    CSHORT DataLength;
-    CSHORT TotalLength;
-} _PORT_MESSAGE_TMP_SUBSTRUCT_S1;
-
-
-typedef union _PORT_MESSAGE_TMP_UNION_U1
-{
-    ULONG Length;
-    _PORT_MESSAGE_TMP_SUBSTRUCT_S1 s1;
-} _PORT_MESSAGE_TMP_UNION_U1;
-
-
-typedef struct _PORT_MESSAGE_TMP_SUBSTRUCT_S2
-{
-    CSHORT Type;
-    CSHORT DataInfoOffset;
-} _PORT_MESSAGE_TMP_SUBSTRUCT_S2;
-
-
-typedef union _PORT_MESSAGE_TMP_UNION_U2
-{
-        ULONG ZeroInit;
-        _PORT_MESSAGE_TMP_SUBSTRUCT_S2 s2;
-} _PORT_MESSAGE_TMP_UNION_U2;
-
-
-typedef struct _PORT_MESSAGE32
-{
-    _PORT_MESSAGE_TMP_UNION_U1 u1;
-    _PORT_MESSAGE_TMP_UNION_U2 u2;
-    CLIENT_ID32 ClientId;
-    ULONG MessageId;
-    _PORT_MESSAGE32_TMP_UNION tmp_union;
-} PORT_MESSAGE32, *PPORT_MESSAGE32;
-
-typedef struct _PORT_MESSAGE64
-{
-    _PORT_MESSAGE_TMP_UNION_U1 u1;
-    _PORT_MESSAGE_TMP_UNION_U2 u2;
-    CLIENT_ID64 ClientId;
-    ULONG MessageId;
-    _PORT_MESSAGE64_TMP_UNION tmp_union;
-} PORT_MESSAGE64, *PPORT_MESSAGE64;
-
-
-typedef struct _ALPC_SERVER_INFORMATION_TMP_IN
-{
-    HANDLE ThreadHandle;
-} ALPC_SERVER_INFORMATION_TMP_IN;
-
-typedef struct _ALPC_SERVER_INFORMATION_TMP_OUT
-{
-    BOOLEAN ThreadBlocked;
-    HANDLE ConnectedProcessId;
-    UNICODE_STRING ConnectionPortName;
-} ALPC_SERVER_INFORMATION_TMP_OUT;
-
-typedef union ALPC_SERVER_INFORMATION
-{
-    ALPC_SERVER_INFORMATION_TMP_IN In;
-    ALPC_SERVER_INFORMATION_TMP_OUT Out;
-} ALPC_SERVER_INFORMATION;
-
-
-typedef struct _ALPC_CONTEXT_ATTR
-{
-    PVOID PortContext;
-    PVOID MessageContext;
-    ULONG Sequence;
-    ULONG MessageId;
-    ULONG CallbackId;
-} ALPC_CONTEXT_ATTR, *PALPC_CONTEXT_ATTR;
-
-typedef struct _ALPC_CONTEXT_ATTR32
-{
-    ULONG PortContext;
-    ULONG MessageContext;
-    ULONG Sequence;
-    ULONG MessageId;
-    ULONG CallbackId;
-} ALPC_CONTEXT_ATTR32, *PALPC_CONTEXT_ATTR32;
-
-typedef struct _ALPC_CONTEXT_ATTR64
-{
-    ULONGLONG PortContext;
-    ULONGLONG MessageContext;
-    ULONG Sequence;
-    ULONG MessageId;
-    ULONG CallbackId;
-} ALPC_CONTEXT_ATTR64, *PALPC_CONTEXT_ATTR64;
-
-
-typedef struct _ALPC_HANDLE_ATTR
-{
-    ULONG Flags;
-    HANDLE Handle;
-    ULONG ObjectType;
-    ACCESS_MASK DesiredAccess;
-} ALPC_HANDLE_ATTR, *PALPC_HANDLE_ATTR;
-
-typedef struct _ALPC_HANDLE_ATTR32
-{
-    ULONG Flags;
-    ULONG Handle;
-    ULONG ObjectType;
-    ACCESS_MASK DesiredAccess;
-} ALPC_HANDLE_ATTR32, *PALPC_HANDLE_ATTR32;
-
-
-typedef struct _ALPC_HANDLE_ATTR64
-{
-    ULONG Flags;
-    ULONGLONG Handle;
-    ULONG ObjectType;
-    ACCESS_MASK DesiredAccess;
-} ALPC_HANDLE_ATTR64, *PALPC_HANDLE_ATTR64;
-
-
-typedef struct _ALPC_SECURITY_ATTR
-{
-    ULONG Flags;
-    PSECURITY_QUALITY_OF_SERVICE QoS;
-    ALPC_HANDLE ContextHandle;
-} ALPC_SECURITY_ATTR, *PALPC_SECURITY_ATTR;
-
-typedef struct _ALPC_SECURITY_ATTR32
-{
-    ULONG Flags;
-    ULONG QoS;
-    ULONG ContextHandle;
-} ALPC_SECURITY_ATTR32, *PALPC_SECURITY_ATTR32;
-
-
-typedef struct _ALPC_SECURITY_ATTR64
-{
-    ULONGLONG Flags;
-    ULONGLONG QoS;
-    ULONGLONG ContextHandle;
-} ALPC_SECURITY_ATTR64, *PALPC_SECURITY_ATTR64;
-
-typedef struct _ALPC_DATA_VIEW_ATTR
-{
-    ULONG Flags;
-    ALPC_HANDLE SectionHandle;
-    PVOID ViewBase;
-    PVOID ViewSize;
-} ALPC_DATA_VIEW_ATTR, *PALPC_DATA_VIEW_ATTR;
-
-typedef struct _ALPC_DATA_VIEW_ATTR32
-{
-    ULONG Flags;
-    ULONG SectionHandle;
-    ULONG ViewBase;
-    ULONG ViewSize;
-} ALPC_DATA_VIEW_ATTR32, *PALPC_DATA_VIEW_ATTR32;
-
-
-typedef struct _ALPC_DATA_VIEW_ATTR64
-{
-    ULONG Flags;
-    ULONGLONG SectionHandle;
-    ULONGLONG ViewBase;
-    ULONGLONG ViewSize;
-} ALPC_DATA_VIEW_ATTR64, *PALPC_DATA_VIEW_ATTR64;
-
-
-typedef struct _ALPC_TOKEN_ATTR
-{
-    ULONGLONG TokenId;
-    ULONGLONG AuthenticationId;
-    ULONGLONG ModifiedId;
-} ALPC_TOKEN_ATTR, *PALPC_TOKEN_ATTR;
-
-
-typedef struct _ALPC_DIRECT_ATTR
-{
-    HANDLE Event;
-} ALPC_DIRECT_ATTR, *PALPC_DIRECT_ATTR;
-
-typedef struct _ALPC_DIRECT_ATTR32
-{
-    ULONG Event;
-} ALPC_DIRECT_ATTR32, *PALPC_DIRECT_ATTR32;
-
-typedef struct _ALPC_DIRECT_ATTR64
-{
-    ULONGLONG Event;
-} ALPC_DIRECT_ATTR64, *PALPC_DIRECT_ATTR64;
-
-
-typedef struct _ALPC_WORK_ON_BEHALF_ATTR
-{
-    ULONGLONG Ticket;
-} ALPC_WORK_ON_BEHALF_ATTR, *PALPC_WORK_ON_BEHALF_ATTR;
-
-typedef struct _RPC_IF_ID {
-  IID           Uuid;
-  USHORT VersMajor;
-  USHORT VersMinor;
-} RPC_IF_ID;
diff --git a/samples/rpc/uac.py b/samples/rpc/uac.py
index 41d8e27..83bdce8 100644
--- a/samples/rpc/uac.py
+++ b/samples/rpc/uac.py
@@ -52,12 +52,12 @@ iid = client.bind(UAC_UIID)
 
 # Marshalling parameters.
 parameters = RAiLaunchAdminProcessParameters.pack([
-    params.target + "\x00", # Application Path
-    params.cmdline + "\x00", # Commandline
+    params.target, # Application Path
+    params.cmdline, # Commandline
     params.uacflags, # UAC-Request Flag
     params.creationflags, # dwCreationFlags
-    "\x00", # StartDirectory
-    "WinSta0\\Default\x00", # Station
+    "", # StartDirectory
+    "WinSta0\\Default", # Station
         # Startup Info
         (None, # Title
         0, # dwX
diff --git a/windows/rpc/ndr.py b/windows/rpc/ndr.py
index a3025d5..5c3ac11 100644
--- a/windows/rpc/ndr.py
+++ b/windows/rpc/ndr.py
@@ -100,6 +100,7 @@ class NdrSID(object):
 class NdrVaryingCString(object):
     @classmethod
     def pack(cls, data):
+        """Pack string ``data``. append ``\\x00`` if not present at the end of the string"""
         if data is None:
             return None
         if not data.endswith('\x00'):
@@ -112,6 +113,7 @@ class NdrVaryingCString(object):
 class NdrWString(object):
     @classmethod
     def pack(cls, data):
+        """Pack string ``data``. append ``\\x00`` if not present at the end of the string"""
         if data is None:
             return None
         if not data.endswith('\x00'):
@@ -134,6 +136,7 @@ class NdrWString(object):
 class NdrCString(object):
     @classmethod
     def pack(cls, data):
+        """Pack string ``data``. append ``\\x00`` if not present at the end of the string"""
         if data is None:
             return None
         if not data.endswith('\x00'):
@@ -168,7 +171,7 @@ class NdrHyper(object):
 
     @classmethod
     def unpack(self, stream):
-        stream.align(4)
+        stream.align(8)
         return stream.partial_unpack("<Q")[0]
 
 class NdrShort(object):
@@ -191,6 +194,18 @@ class NdrByte(object):
         return stream.partial_unpack("<B")[0]
 
 
+class NdrGuid(object):
+    @classmethod
+    def pack(cls, data):
+        if not isinstance(data, gdef.IID):
+            data = gdef.IID.from_string(data)
+        return str(bytearray(data))
+
+    @classmethod
+    def unpack(self, stream):
+        rawguid = stream.partial_unpack("16s")[0]
+        return gdef.IID.from_buffer_copy(rawguid)
+
 class NdrContextHandle(object):
     @classmethod
     def pack(cls, data):
@@ -252,15 +267,17 @@ class NdrStructure(object):
                 data.append(member.unpack_conformant(stream, conformant_size))
             else:
                 if hasattr(member, "unpack_in_struct"):
+                    # print("[{0}] Dereferenced unpacking".format(i))
                     ptr, subcls = member.unpack_in_struct(stream)
                     if not ptr:
                         data.append(None)
                     else:
                         data.append(ptr)
                     post_subcls.append((i, subcls))
-                    print(post_subcls)
+                    # print(post_subcls)
                 else:
                     data.append(member.unpack(stream))
+        # print("Applying deref unpack")
         for i, entry in post_subcls:
             data[i] = entry.unpack(stream)
         return cls.post_unpack(data)
@@ -369,13 +386,27 @@ class NdrWcharConformantVaryingArrays(NdrConformantVaryingArrays):
         return u"".join(unichr(c) for c in result)
 
 
+class NdrHyperConformantVaryingArrays(NdrConformantVaryingArrays):
+    MEMBER_TYPE = NdrHyper
+
+class NdrHyperConformantArray(NdrConformantArray):
+    MEMBER_TYPE = NdrHyper
+
 class NdrLongConformantArray(NdrConformantArray):
     MEMBER_TYPE = NdrLong
 
+class NdrShortConformantArray(NdrConformantArray):
+    MEMBER_TYPE = NdrShort
 
 class NdrByteConformantArray(NdrConformantArray):
     MEMBER_TYPE = NdrByte
 
+    @classmethod
+    def _post_unpack(self, result):
+        return bytearray(result)
+
+class NdrGuidConformantArray(NdrConformantArray):
+    MEMBER_TYPE = NdrGuid
 
 
 class NdrStream(object):
@@ -412,6 +443,8 @@ class NdrStream(object):
             # Realign
             size_to_align = (size - (already_read % size))
             self.data = self.data[size_to_align:]
+            return size_to_align
+        return 0
 
 
 def make_parameters(types, name=None):
diff --git a/windows/winobject/token.py b/windows/winobject/token.py
index 6739b7c..f9215fb 100644
--- a/windows/winobject/token.py
+++ b/windows/winobject/token.py
@@ -594,15 +594,20 @@ class Token(utils.AutoHandle):
             buffsize = ctypes.sizeof(privileges)
         winproxy.AdjustTokenPrivileges(self.handle, False, privileges, buffsize, None, None)
         if winproxy.GetLastError() == gdef.ERROR_NOT_ALL_ASSIGNED:
-            raise ValueError("Failed to adjust all privileges")
+            # Transform this in a real WindowsError
+            raise WindowsError(gdef.ERROR_NOT_ALL_ASSIGNED, "Failed to adjust all privileges")
 
     def enable_privilege(self, name):
-        """Enable privilege ``name`` in the token"""
+        """Enable privilege ``name`` in the token
+
+        :raises: :class:`ValueError` if :class:`Token` has no privilege ``name``
+        """
         privs = self.privileges
         try:
             privs[name] = gdef.SE_PRIVILEGE_ENABLED
         except KeyError as e:
-            raise ValueError("{0} as no privilege <{1}>".format(self, name))
+            # Emulate the WindowsError that would be triggered in 'adjust_privileges' ?
+            raise ValueError("{0} has no privilege <{1}>".format(self, name))
         return self.adjust_privileges(privs)
 
     def __repr__(self):
diff --git a/windows/winproxy/apiproxy.py b/windows/winproxy/apiproxy.py
index 8131e01..ffce0bd 100644
--- a/windows/winproxy/apiproxy.py
+++ b/windows/winproxy/apiproxy.py
@@ -82,7 +82,13 @@ class ApiProxy(object):
 
         def generate_ctypes_function():
             try:
-                c_prototyped = prototype((self.func_name, getattr(ctypes.windll, self.APIDLL)), params)
+                api_dll = ctypes.windll[self.APIDLL]
+            except WindowsError as e:
+                if e.winerror == gdef.ERROR_BAD_EXE_FORMAT:
+                    e.strerror = e.strerror.replace("%1", "<{0}>".format(self.APIDLL))
+                raise
+            try:
+                c_prototyped = prototype((self.func_name, api_dll), params)
             except (AttributeError, WindowsError):
                 raise ExportNotFound(self.func_name, self.APIDLL)
             if self.error_check is not None: