diff --git a/sysinfo_win32.cpp b/sysinfo_win32.cpp
index e1290350..5b61f032 100644
--- a/sysinfo_win32.cpp
+++ b/sysinfo_win32.cpp
@@ -21,11 +21,12 @@ cruft::util::operator<< (std::ostream &os, sysinfo const &)
     os << "{ ";
 
     {
-        OSVERSIONINFO version;
+        OSVERSIONINFO version {};
+        version.dwOSVersionInfoSize = sizeof (OSVERSIONINFO);
         if (!GetVersionExA (&version))
             win32::error::throw_code ();
 
-        os << "os: { name: win32, "
+        os << "os: { name: win32"
                << ", version: " << +version.dwMajorVersion << '.'
                                 << +version.dwMinorVersion << '.'
                                 << +version.dwPlatformId
@@ -36,23 +37,33 @@ cruft::util::operator<< (std::ostream &os, sysinfo const &)
     std::string name;
 
     {
-        if (!GetComputerNameExA (ComputerNamePhysicalNetBIOS, nullptr, &size))
+        if (0 == GetComputerNameExA (ComputerNamePhysicalNetBIOS, nullptr, &size)) {
+            auto const code = win32::error::last_code ();
+            if (code != ERROR_MORE_DATA)
+                win32::error::throw_code (code);
+        }
+        name.resize (size);
+
+        if (0 == GetComputerNameExA (ComputerNamePhysicalNetBIOS, &name[0], &size))
             win32::error::throw_code ();
         name.resize (size);
 
-        if (!GetComputerNameExA (ComputerNamePhysicalNetBIOS, &name[0], &size))
-            win32::error::throw_code ();
         os << ", hostname: " << name;
     }
 
     {
         size = 0;
-        if (!GetUserNameA (nullptr, &size))
-            win32::error::throw_code ();
+        if (0 == GetUserNameA (nullptr, &size)) {
+            auto const code = win32::error::last_code ();
+            if (code != ERROR_INSUFFICIENT_BUFFER)
+                win32::error::throw_code (code);
+
+        }
         name.resize (size);
 
-        if (!GetUserNameA (&name[0], &size))
+        if (0 == GetUserNameA (&name[0], &size))
             win32::error::throw_code ();
+        name.resize (size);
 
         os << ", username: " << name;
     }
@@ -61,7 +72,7 @@ cruft::util::operator<< (std::ostream &os, sysinfo const &)
         MEMORYSTATUSEX status {};
         status.dwLength = sizeof (status);
 
-        if (!GlobalMemoryStatusEx (&status))
+        if (0 == GlobalMemoryStatusEx (&status))
             win32::error::throw_code ();
 
         os << ", ram: { total: " << status.ullTotalPhys << ", available: " << status.ullAvailPhys << " },";