diff --git a/lib/boinc_cmd.C b/lib/boinc_cmd.C
index 39d51b4534..5dd993072c 100644
--- a/lib/boinc_cmd.C
+++ b/lib/boinc_cmd.C
@@ -129,7 +129,7 @@ void read_password_from_file(char* buf) {
 	FILE* f = fopen("gui_rpc_auth.cfg", "r");
 	if (!f) return;
 	fgets(buf, 256, f);
-	int n = strlen(buf);
+	int n = (int)strlen(buf);
 
 	// trim CR
 	//
diff --git a/lib/diagnostics_win.C b/lib/diagnostics_win.C
index efb93eeeb9..d1881aa0ff 100644
--- a/lib/diagnostics_win.C
+++ b/lib/diagnostics_win.C
@@ -364,8 +364,6 @@ int diagnostics_update_thread_list_NT() {
     PSYSTEM_PROCESSES_NT4   pProcesses = NULL;
     PSYSTEM_THREADS         pThread = NULL;
     UINT                    uiSystemIndex = 0;
-    UINT                    uiInternalIndex = 0;
-    UINT                    uiInternalCount = 0;
     HMODULE                 hKernel32Lib;
     tOT                     pOT = NULL;
 
@@ -457,8 +455,6 @@ int diagnostics_update_thread_list_XP() {
     PSYSTEM_PROCESSES       pProcesses = NULL;
     PSYSTEM_THREADS         pThread = NULL;
     UINT                    uiSystemIndex = 0;
-    UINT                    uiInternalIndex = 0;
-    UINT                    uiInternalCount = 0;
     HMODULE                 hKernel32Lib;
     tOT                     pOT = NULL;
 
@@ -1141,7 +1137,7 @@ int diagnostics_message_monitor_dump() {
 //
 // See: http://support.microsoft.com/kb/q173260/
 //
-UINT WINAPI diagnostics_message_monitor(LPVOID lpParameter) {
+UINT WINAPI diagnostics_message_monitor(LPVOID /* lpParameter */) {
     DWORD       dwEvent = NULL;
     DWORD       dwCurrentProcessId = NULL;
     BOOL        bContinue = TRUE;
@@ -1794,7 +1790,7 @@ UINT diagnostics_determine_exit_code() {
 }
 
 
-UINT WINAPI diagnostics_unhandled_exception_monitor(LPVOID lpParameter) {
+UINT WINAPI diagnostics_unhandled_exception_monitor(LPVOID /* lpParameter */) {
     DWORD        dwEvent = NULL;
     BOOL         bContinue = TRUE;
     BOOL         bDebuggerInitialized = FALSE;
@@ -1940,7 +1936,7 @@ UINT WINAPI diagnostics_unhandled_exception_monitor(LPVOID lpParameter) {
 
                 // Force terminate the app letting BOINC know an exception has occurred.
                 if (diagnostics_is_aborted_via_gui()) {
-                    TerminateProcess(GetCurrentProcess(), ERR_ABORTED_VIA_GUI);
+                    TerminateProcess(GetCurrentProcess(), (UINT)ERR_ABORTED_VIA_GUI);
                 } else {
                     TerminateProcess(GetCurrentProcess(), diagnostics_determine_exit_code());
                 }
diff --git a/lib/stackwalker_win.cpp b/lib/stackwalker_win.cpp
index a1926c5acb..5ecc27a03a 100644
--- a/lib/stackwalker_win.cpp
+++ b/lib/stackwalker_win.cpp
@@ -121,7 +121,7 @@ bool DebuggerLoadLibrary(
     return true;
 }
 
-BOOL CALLBACK SymbolServerCallbackProc(UINT_PTR ActionCode, ULONG64 CallbackData, ULONG64 UserContext)
+BOOL CALLBACK SymbolServerCallbackProc(UINT_PTR ActionCode, ULONG64 CallbackData, ULONG64 /* UserContext */)
 {
     BOOL bRetVal = FALSE;
     PIMAGEHLP_CBA_EVENT pEvent = NULL;
@@ -154,7 +154,7 @@ BOOL CALLBACK SymbolServerCallbackProc(UINT_PTR ActionCode, ULONG64 CallbackData
     return bRetVal;
 }
 
-BOOL CALLBACK SymRegisterCallbackProc(HANDLE hProcess, ULONG ActionCode, ULONG64 CallbackData, ULONG64 UserContext)
+BOOL CALLBACK SymRegisterCallbackProc(HANDLE /* hProcess */, ULONG ActionCode, ULONG64 CallbackData, ULONG64 /* UserContext */)
 {
     BOOL bRetVal = FALSE;
     PIMAGEHLP_CBA_EVENT pEvent = NULL;
@@ -187,7 +187,7 @@ BOOL CALLBACK SymRegisterCallbackProc(HANDLE hProcess, ULONG ActionCode, ULONG64
     return bRetVal;
 }
 
-BOOL CALLBACK SymEnumerateModulesProc(LPSTR ModuleName, DWORD64 BaseOfDll, PVOID UserContext)
+BOOL CALLBACK SymEnumerateModulesProc(LPSTR /* ModuleName */, DWORD64 BaseOfDll, PVOID /* UserContext */)
 {
     IMAGEHLP_MODULE64   Module;
     char                szSymbolType[32];
@@ -514,8 +514,6 @@ int DebuggerInitialize( LPCSTR pszBOINCLocation, LPCSTR pszSymbolStore, BOOL bPr
     std::string strLocalSymbolStore;
     std::string strSymbolSearchPath;
 
-    static const std::basic_string<char>::size_type npos = -1;
-
     tt = (CHAR*) malloc(sizeof(CHAR) * TTBUFLEN); // Get the temporary buffer
     if (!tt) return 1;  // not enough memory...
 
@@ -558,21 +556,21 @@ int DebuggerInitialize( LPCSTR pszBOINCLocation, LPCSTR pszSymbolStore, BOOL bPr
         strLocalSymbolStore += tt + std::string("symbols");
 
     // microsoft public symbol server
-    if (npos == strSymbolSearchPath.find("http://msdl.microsoft.com/download/symbols")) {
+    if (std::string::npos == strSymbolSearchPath.find("http://msdl.microsoft.com/download/symbols")) {
         strSymbolSearchPath += 
             std::string( "srv*" ) + strLocalSymbolStore + 
             std::string( "*http://msdl.microsoft.com/download/symbols;" );
     }
 
     // project symbol server
-    if ((npos == strSymbolSearchPath.find(pszSymbolStore)) && (0 < strlen(pszSymbolStore))) {
+    if ((std::string::npos == strSymbolSearchPath.find(pszSymbolStore)) && (0 < strlen(pszSymbolStore))) {
         strSymbolSearchPath += 
             std::string( "srv*" ) + strLocalSymbolStore + std::string( "*" ) +
             std::string( pszSymbolStore ) + std::string( ";" );
     }
 
     // boinc symbol server
-    if (npos == strSymbolSearchPath.find("http://boinc.berkeley.edu/symstore")) {
+    if (std::string::npos == strSymbolSearchPath.find("http://boinc.berkeley.edu/symstore")) {
         strSymbolSearchPath += 
             std::string( "srv*" ) + strLocalSymbolStore + 
             std::string( "*http://boinc.berkeley.edu/symstore;" );
@@ -689,9 +687,9 @@ static void ShowStackRM(HANDLE hThread, CONTEXT& Context)
 {
     BOOL bRetVal = FALSE;
 
-    int frameNum;
-    DWORD64 offsetFromSymbol;
-    DWORD offsetFromLine;
+    int frameNum = 0;
+    DWORD64 offsetFromSymbol = 0;
+    DWORD offsetFromLine = 0;
     char undName[MAX_SYM_NAME];
 
     char szMsgSymFromAddr[256];