diff --git a/reactos/dll/ntdll/def/ntdll.pspec b/reactos/dll/ntdll/def/ntdll.pspec
index 0ce536711f4..53ff18032c8 100644
--- a/reactos/dll/ntdll/def/ntdll.pspec
+++ b/reactos/dll/ntdll/def/ntdll.pspec
@@ -683,7 +683,7 @@
 @ stdcall RtlGetSaclSecurityDescriptor(ptr ptr ptr ptr)
 @ stdcall RtlGetSecurityDescriptorRMControl(ptr ptr)
 @ stdcall RtlGetSetBootStatusData(ptr long long ptr long long)
-//@ stdcall RtlGetThreadErrorMode
+@ stdcall RtlGetThreadErrorMode()
 //@ stdcall RtlGetUnloadEventTrace
 @ stdcall RtlGetUserInfoHeap(ptr long ptr ptr ptr)
 @ stdcall RtlGetVersion(ptr)
@@ -894,7 +894,7 @@
 @ stdcall RtlSetSecurityDescriptorRMControl(ptr ptr)
 @ stdcall RtlSetSecurityObject(long ptr ptr ptr ptr)
 //@ stdcall RtlSetSecurityObjectEx
-//@ stdcall RtlSetThreadErrorMode
+@ stdcall RtlSetThreadErrorMode(long ptr)
 @ stdcall RtlSetThreadIsCritical(long ptr long)
 @ stdcall RtlSetThreadPoolStartFunc(ptr ptr)
 @ stdcall RtlSetTimeZoneInformation(ptr)
diff --git a/reactos/dll/ntdll/def/ntdll.spec b/reactos/dll/ntdll/def/ntdll.spec
index 9a9deff0689..c9f5c2ecbcc 100644
--- a/reactos/dll/ntdll/def/ntdll.spec
+++ b/reactos/dll/ntdll/def/ntdll.spec
@@ -681,7 +681,7 @@
 @ stdcall RtlGetSaclSecurityDescriptor(ptr ptr ptr ptr)
 @ stdcall RtlGetSecurityDescriptorRMControl(ptr ptr)
 @ stdcall RtlGetSetBootStatusData(ptr long long ptr long long)
-;@ stdcall RtlGetThreadErrorMode
+@ stdcall RtlGetThreadErrorMode()
 ;@ stdcall RtlGetUnloadEventTrace
 @ stdcall RtlGetUserInfoHeap(ptr long ptr ptr ptr)
 @ stdcall RtlGetVersion(ptr)
@@ -894,7 +894,7 @@
 @ stdcall RtlSetSecurityDescriptorRMControl(ptr ptr)
 @ stdcall RtlSetSecurityObject(long ptr ptr ptr ptr)
 ;@ stdcall RtlSetSecurityObjectEx
-;@ stdcall RtlSetThreadErrorMode
+@ stdcall RtlSetThreadErrorMode(long ptr)
 @ stdcall RtlSetThreadIsCritical(long ptr long)
 @ stdcall RtlSetThreadPoolStartFunc(ptr ptr)
 @ stdcall RtlSetTimeZoneInformation(ptr)
diff --git a/reactos/lib/rtl/error.c b/reactos/lib/rtl/error.c
index 5396f142396..bcbf3e3e0a4 100644
--- a/reactos/lib/rtl/error.c
+++ b/reactos/lib/rtl/error.c
@@ -24,6 +24,10 @@
 #define NDEBUG
 #include <debug.h>
 
+#define RTL_SEM_FAILCRITICALERRORS      (SEM_FAILCRITICALERRORS << 4)
+#define RTL_SEM_NOGPFAULTERRORBOX       (SEM_NOGPFAULTERRORBOX << 4)
+#define RTL_SEM_NOALIGNMENTFAULTEXCEPT  (SEM_NOALIGNMENTFAULTEXCEPT << 4)
+
 struct error_table
 {
     DWORD       start;
@@ -171,6 +175,44 @@ RtlMapSecurityErrorToNtStatus(
     return STATUS_NOT_IMPLEMENTED;
 }
 
+/*
+ * @implemented
+ */
+NTSTATUS
+NTAPI
+RtlSetThreadErrorMode(IN ULONG NewMode,
+                      OUT PULONG OldMode OPTIONAL)
+{
+    PTEB Teb = NtCurrentTeb();
+
+    /* Ignore invalid error modes */
+    if (NewMode & ~(RTL_SEM_FAILCRITICALERRORS |
+                    RTL_SEM_NOGPFAULTERRORBOX |
+                    RTL_SEM_NOALIGNMENTFAULTEXCEPT))
+    {
+        DPRINT1("Invalid error mode\n");
+        return STATUS_INVALID_PARAMETER_1;
+    }
+
+    /* Return old mode */
+    if (OldMode) *OldMode = Teb->HardErrorMode;
+    
+    /* Set new one and return success */
+    Teb->HardErrorMode = NewMode;
+    return STATUS_SUCCESS;
+}
+
+/*
+ * @implemented
+ */
+ULONG
+NTAPI
+RtlGetThreadErrorMode(VOID)
+{
+    /* Return it from the TEB */
+    return NtCurrentTeb()->HardErrorMode;
+}
+
 /* conversion tables */
 
 static const DWORD table_00000102[32] =
diff --git a/reactos/lib/rtl/network.c b/reactos/lib/rtl/network.c
index 3b0979ed302..d3b4a9881e1 100644
--- a/reactos/lib/rtl/network.c
+++ b/reactos/lib/rtl/network.c
@@ -31,18 +31,13 @@ NTAPI
 RtlIpv4AddressToStringA(IN struct in_addr *Addr,
                         OUT PCHAR S)
 {
-    CHAR Buffer[IPV4_ADDR_STRING_MAX_LEN];
     INT Length;
 
-    if(!S)
-        return NULL;
-
-    Length = sprintf(Buffer, "%u.%u.%u.%u", Addr->S_un.S_un_b.s_b1,
+    Length = sprintf(S, "%u.%u.%u.%u", Addr->S_un.S_un_b.s_b1,
                                             Addr->S_un.S_un_b.s_b2,
                                             Addr->S_un.S_un_b.s_b3,
                                             Addr->S_un.S_un_b.s_b4);
 
-    strcpy(S, Buffer);
     return S + Length;
 }
 
@@ -88,19 +83,12 @@ NTAPI
 RtlIpv4AddressToStringW(IN struct in_addr *Addr,
                         OUT PWCHAR S)
 {
-    WCHAR Buffer[IPV4_ADDR_STRING_MAX_LEN];
     INT Length;
 
-    if (!S)
-        return NULL;
-
-    Length = swprintf(Buffer, L"%u.%u.%u.%u", Addr->S_un.S_un_b.s_b1,
-                                              Addr->S_un.S_un_b.s_b2,
-                                              Addr->S_un.S_un_b.s_b3,
-                                              Addr->S_un.S_un_b.s_b4);
-
-    wcscpy(S, Buffer);
-
+    Length = swprintf(S, L"%u.%u.%u.%u", Addr->S_un.S_un_b.s_b1,
+                                         Addr->S_un.S_un_b.s_b2,
+                                         Addr->S_un.S_un_b.s_b3,
+                                         Addr->S_un.S_un_b.s_b4);
     return S + Length;
 }