diff --git a/src/common/system.cpp b/src/common/system.cpp
index 72e9de100be6..2c302378c151 100644
--- a/src/common/system.cpp
+++ b/src/common/system.cpp
@@ -13,7 +13,6 @@
 
 #ifdef WIN32
 #include <cassert>
-#include <codecvt>
 #include <compat/compat.h>
 #include <windows.h>
 #else
@@ -56,7 +55,8 @@ void runCommand(const std::string& strCommand)
 #ifndef WIN32
     int nErr = ::system(strCommand.c_str());
 #else
-    int nErr = ::_wsystem(std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>,wchar_t>().from_bytes(strCommand).c_str());
+    const std::wstring wide_command{util::Utf8ToWide(strCommand)};
+    int nErr = ::_wsystem(wide_command.c_str());
 #endif
     if (nErr) {
         LogWarning("runCommand error: system(%s) returned %d", strCommand, nErr);
diff --git a/src/leveldb/util/env_windows.cc b/src/leveldb/util/env_windows.cc
index 8897e2aa26b9..e33f83c813b5 100644
--- a/src/leveldb/util/env_windows.cc
+++ b/src/leveldb/util/env_windows.cc
@@ -81,11 +81,6 @@ class ScopedHandle {
 
   ScopedHandle& operator=(const ScopedHandle&) = delete;
 
-  ScopedHandle& operator=(ScopedHandle&& rhs) noexcept {
-    if (this != &rhs) handle_ = rhs.Release();
-    return *this;
-  }
-
   bool Close() {
     if (!is_valid()) {
       return true;
diff --git a/src/util/exec.cpp b/src/util/exec.cpp
index 6b1406134268..af293d828096 100644
--- a/src/util/exec.cpp
+++ b/src/util/exec.cpp
@@ -5,6 +5,7 @@
 #include <util/exec.h>
 
 #include <util/fs.h>
+#include <util/string.h>
 #include <util/subprocess.h>
 
 #include <string>
@@ -24,16 +25,16 @@ int ExecVp(const char* file, char* const argv[])
     return execvp(file, argv);
 #else
     std::vector<std::wstring> escaped_args;
-    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> converter;
     for (char* const* arg_ptr{argv}; *arg_ptr; ++arg_ptr) {
-        subprocess::util::quote_argument(converter.from_bytes(*arg_ptr), escaped_args.emplace_back(), false);
+        subprocess::util::quote_argument(util::Utf8ToWide(*arg_ptr), escaped_args.emplace_back(), false);
     }
 
     std::vector<const wchar_t*> new_argv;
     new_argv.reserve(escaped_args.size() + 1);
     for (const auto& s : escaped_args) new_argv.push_back(s.c_str());
     new_argv.push_back(nullptr);
-    return _wexecvp(converter.from_bytes(file).c_str(), new_argv.data());
+    const std::wstring wide_file{util::Utf8ToWide(file)};
+    return _wexecvp(wide_file.c_str(), new_argv.data());
 #endif
 }
 
diff --git a/src/util/string.cpp b/src/util/string.cpp
index 507d9d317182..56cd78871256 100644
--- a/src/util/string.cpp
+++ b/src/util/string.cpp
@@ -4,6 +4,18 @@
 
 #include <util/string.h>
 
+#ifdef WIN32
+#include <util/syserror.h>
+
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+#include <windows.h>
+
+#include <limits>
+#include <stdexcept>
+#endif
+
 #include <regex>
 #include <string>
 
@@ -13,4 +25,30 @@ void ReplaceAll(std::string& in_out, const std::string& search, const std::strin
     if (search.empty()) return;
     in_out = std::regex_replace(in_out, std::regex(search), substitute);
 }
+
+#ifdef WIN32
+std::wstring Utf8ToWide(std::string_view utf8)
+{
+    if (utf8.empty()) return {};
+    if (utf8.size() > static_cast<size_t>(std::numeric_limits<int>::max())) {
+        throw std::runtime_error("UTF-8 string is too long to convert");
+    }
+
+    const int src_size{static_cast<int>(utf8.size())};
+    const int dst_size{MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8.data(), src_size, nullptr, 0)};
+    if (dst_size == 0) {
+        const auto err{GetLastError()};
+        throw std::runtime_error("MultiByteToWideChar failed: " + Win32ErrorString(err));
+    }
+
+    std::wstring wide(dst_size, 0);
+    const int result{MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8.data(), src_size, wide.data(), dst_size)};
+    if (result != dst_size) {
+        const auto err{GetLastError()};
+        throw std::runtime_error("MultiByteToWideChar failed: " + Win32ErrorString(err));
+    }
+
+    return wide;
+}
+#endif
 } // namespace util
diff --git a/src/util/string.h b/src/util/string.h
index 330c2a2a61e0..d12e4c616472 100644
--- a/src/util/string.h
+++ b/src/util/string.h
@@ -260,6 +260,10 @@ template <typename T1, size_t PREFIX_LEN>
     return obj.size() >= PREFIX_LEN &&
            std::equal(std::begin(prefix), std::end(prefix), std::begin(obj));
 }
+
+#ifdef WIN32
+std::wstring Utf8ToWide(std::string_view utf8);
+#endif
 } // namespace util
 
 #endif // BITCOIN_UTIL_STRING_H
diff --git a/src/util/subprocess.h b/src/util/subprocess.h
index e90c165205ee..4ec0a09265f6 100644
--- a/src/util/subprocess.h
+++ b/src/util/subprocess.h
@@ -37,6 +37,7 @@ Documentation for C++ subprocessing library.
 #define BITCOIN_UTIL_SUBPROCESS_H
 
 #include <util/syserror.h>
+#include <util/string.h>
 
 #include <algorithm>
 #include <cassert>
@@ -59,10 +60,6 @@ Documentation for C++ subprocessing library.
   #define __USING_WINDOWS__
 #endif
 
-#ifdef __USING_WINDOWS__
-  #include <codecvt>
-#endif
-
 extern "C" {
 #ifdef __USING_WINDOWS__
   #include <windows.h>
@@ -743,6 +740,7 @@ struct ArgumentDeducer
  * This takes care of all the fork-exec logic
  * in the execute_child API.
  */
+#ifndef __USING_WINDOWS__
 class Child
 {
 public:
@@ -759,6 +757,7 @@ class Child
   Popen* parent_ = nullptr;
   int err_wr_pipe_ = -1;
 };
+#endif // !__USING_WINDOWS__
 
 // Fwd Decl.
 class Streams;
@@ -932,7 +931,9 @@ class Popen
 {
 public:
   friend struct detail::ArgumentDeducer;
+#ifndef __USING_WINDOWS__
   friend class detail::Child;
+#endif
 
   template <typename... Args>
   Popen(const std::string& cmd_args, Args&& ...args):
@@ -1035,7 +1036,9 @@ class Popen
   std::vector<char*> cargv_;
 
   // Pid of the child process
+#ifndef __USING_WINDOWS__
   int child_pid_ = -1;
+#endif
 
   int retcode_ = -1;
 };
@@ -1102,7 +1105,6 @@ inline void Popen::execute_process() noexcept(false)
   }
   this->exe_name_ = vargs_[0];
 
-  std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> converter;
   std::wstring argument;
   std::wstring command_line;
   bool first_arg = true;
@@ -1113,7 +1115,7 @@ inline void Popen::execute_process() noexcept(false)
     } else {
       first_arg = false;
     }
-    argument = converter.from_bytes(arg);
+    argument = ::util::Utf8ToWide(arg);
     util::quote_argument(argument, command_line, false);
   }