diff --git a/client/tests/CMakeLists.txt b/client/tests/CMakeLists.txt
index 8b7c87b6..14253d00 100644
--- a/client/tests/CMakeLists.txt
+++ b/client/tests/CMakeLists.txt
@@ -14,6 +14,19 @@ set_tests_properties(common-platform-tests PROPERTIES
   TIMEOUT 10
 )
 
+if(LG_CLIENT_PLATFORM_WINDOWS)
+  add_executable(common-windows-tests
+    common_windows_test.c
+  )
+  target_link_libraries(common-windows-tests
+    ${EXE_FLAGS}
+    lg_common
+  )
+  add_test(NAME common-windows-tests
+    COMMAND common-windows-tests
+  )
+endif()
+
 add_executable(font-tests
   font_test.c
   ../src/font.c
diff --git a/client/tests/common_windows_test.c b/client/tests/common_windows_test.c
new file mode 100644
index 00000000..27c42e91
--- /dev/null
+++ b/client/tests/common_windows_test.c
@@ -0,0 +1,50 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "test.h"
+
+#include "common/win32.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+
+static void testUtfConversion(void)
+{
+  static const char input[] = "Looking Glass \xF0\x9F\x96\xA5";
+
+  wchar_t * wide = lgUtf8ToWide(input);
+  CHECK(wide);
+  CHECK(wcslen(wide) > 0);
+
+  char * output = lgWideToUtf8(wide);
+  CHECK(output);
+  CHECK(strcmp(output, input) == 0);
+  free(output);
+  free(wide);
+
+  CHECK(!lgUtf8ToWide("\xC0\xAF"));
+}
+
+int main(void)
+{
+  testUtfConversion();
+  return 0;
+}
diff --git a/common/include/common/win32.h b/common/include/common/win32.h
new file mode 100644
index 00000000..5460aa17
--- /dev/null
+++ b/common/include/common/win32.h
@@ -0,0 +1,29 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef _H_LG_COMMON_WIN32_
+#define _H_LG_COMMON_WIN32_
+
+#include <wchar.h>
+
+wchar_t * lgUtf8ToWide(const char * input);
+char    * lgWideToUtf8(const wchar_t * input);
+
+#endif
diff --git a/common/src/platform/windows/CMakeLists.txt b/common/src/platform/windows/CMakeLists.txt
index a0d713be..561e264e 100644
--- a/common/src/platform/windows/CMakeLists.txt
+++ b/common/src/platform/windows/CMakeLists.txt
@@ -40,6 +40,9 @@ add_library(lg_common_platform_code STATIC
   windebug.c
   ivshmem.c
   time.c
+  win32.c
+  paths.c
+  open.c
   cpuinfo.c
   display.c
   proctitle.c
@@ -50,6 +53,9 @@ target_link_libraries(lg_common_platform_code
   setupapi
   bcrypt
   ntdll
+  ole32
+  shell32
+  uuid
 )
 
 if (ENABLE_BACKTRACE)
diff --git a/common/src/platform/windows/display.c b/common/src/platform/windows/display.c
index 96611d90..20b9690c 100644
--- a/common/src/platform/windows/display.c
+++ b/common/src/platform/windows/display.c
@@ -23,11 +23,12 @@
 
 bool display_getPathInfo(HMONITOR monitor, DISPLAYCONFIG_PATH_INFO * info)
 {
-  bool result = false;
-  UINT32 numPath, numMode;
+  bool   result = false;
+  UINT32 numPath;
+  UINT32 numMode;
 
   MONITORINFOEXW viewInfo = { .cbSize = sizeof(viewInfo) };
-    if (!GetMonitorInfoW(monitor, (MONITORINFO*)&viewInfo))
+  if (!GetMonitorInfoW(monitor, (MONITORINFO*)&viewInfo))
   {
     DEBUG_ERROR("Failed to get the monitor info");
     goto err;
@@ -37,11 +38,11 @@ err_retry:
   if (FAILED(GetDisplayConfigBufferSizes(QDC_ONLY_ACTIVE_PATHS, &numPath, &numMode)))
     goto err;
 
-  DISPLAYCONFIG_PATH_INFO * pathInfo = calloc(sizeof(*pathInfo), numPath);
+  DISPLAYCONFIG_PATH_INFO * pathInfo = calloc(numPath, sizeof(*pathInfo));
   if (!pathInfo)
     goto err_mem_pathInfo;
 
-  DISPLAYCONFIG_MODE_INFO * modeInfo = calloc(sizeof(*modeInfo), numMode);
+  DISPLAYCONFIG_MODE_INFO * modeInfo = calloc(numMode, sizeof(*modeInfo));
   if (!modeInfo)
     goto err_mem_modeInfo;
 
diff --git a/common/src/platform/windows/open.c b/common/src/platform/windows/open.c
new file mode 100644
index 00000000..c0fc8e13
--- /dev/null
+++ b/common/src/platform/windows/open.c
@@ -0,0 +1,45 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "common/open.h"
+
+#include "common/debug.h"
+#include "common/win32.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <windows.h>
+
+bool lgOpenURL(const char * url)
+{
+  wchar_t * wideUrl = lgUtf8ToWide(url);
+  if (!wideUrl)
+    return false;
+
+  const INT_PTR result = (INT_PTR)ShellExecuteW(
+      NULL, L"open", wideUrl, NULL, NULL, SW_SHOWNORMAL);
+  free(wideUrl);
+  if (result > 32)
+    return true;
+
+  DEBUG_ERROR("Failed to open URL (ShellExecute result: %lld)",
+      (long long)result);
+  return false;
+}
diff --git a/common/src/platform/windows/paths.c b/common/src/platform/windows/paths.c
new file mode 100644
index 00000000..aaefdcd6
--- /dev/null
+++ b/common/src/platform/windows/paths.c
@@ -0,0 +1,116 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "common/paths.h"
+
+#include "common/debug.h"
+#include "common/windebug.h"
+#include "common/win32.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <windows.h>
+#include <knownfolders.h>
+#include <shlobj.h>
+
+static char * configDir;
+static char * dataDir;
+
+static char * makePath(
+    REFKNOWNFOLDERID folderId, const wchar_t * appName)
+{
+  PWSTR         base;
+  const HRESULT status = SHGetKnownFolderPath(folderId, 0, NULL, &base);
+  if (FAILED(status))
+  {
+    DEBUG_WINERROR("Failed to locate application data directory", status);
+    return NULL;
+  }
+
+  const size_t baseLength = wcslen(base);
+  const size_t appLength  = wcslen(appName);
+  if (baseLength > SIZE_MAX - appLength - 2)
+  {
+    CoTaskMemFree(base);
+    return NULL;
+  }
+
+  wchar_t * path = malloc(
+      (baseLength + appLength + 2) * sizeof(*path));
+  if (!path)
+  {
+    CoTaskMemFree(base);
+    return NULL;
+  }
+
+  memcpy(path, base, baseLength * sizeof(*path));
+  path[baseLength] = L'\\';
+  memcpy(path + baseLength + 1, appName,
+      (appLength + 1) * sizeof(*path));
+  CoTaskMemFree(base);
+
+  if (!CreateDirectoryW(path, NULL) && GetLastError() != ERROR_ALREADY_EXISTS)
+  {
+    DEBUG_WINERROR("Failed to create application data directory",
+        GetLastError());
+    free(path);
+    return NULL;
+  }
+
+  char * result = lgWideToUtf8(path);
+  free(path);
+  return result;
+}
+
+void lgPathsInit(const char * appName)
+{
+  wchar_t * wideName = lgUtf8ToWide(appName);
+  if (!wideName)
+  {
+    DEBUG_ERROR("Invalid UTF-8 application name");
+    return;
+  }
+
+  char * newConfigDir = makePath(&FOLDERID_RoamingAppData, wideName);
+  char * newDataDir   = makePath(&FOLDERID_LocalAppData, wideName);
+  free(wideName);
+  if (!newConfigDir || !newDataDir)
+  {
+    free(newConfigDir);
+    free(newDataDir);
+    return;
+  }
+
+  free(configDir);
+  free(dataDir);
+  configDir = newConfigDir;
+  dataDir   = newDataDir;
+}
+
+const char * lgConfigDir(void)
+{
+  return configDir ? configDir : ".";
+}
+
+const char * lgDataDir(void)
+{
+  return dataDir ? dataDir : ".";
+}
diff --git a/common/src/platform/windows/proctitle.c b/common/src/platform/windows/proctitle.c
index b0e8e8e1..848d768b 100644
--- a/common/src/platform/windows/proctitle.c
+++ b/common/src/platform/windows/proctitle.c
@@ -22,6 +22,9 @@
 
 void lgInitProcessTitle(int argc, char **pargv[])
 {
+  (void)argc;
+  (void)pargv;
+
   // not implemented on Windows
 }
 
@@ -32,5 +35,7 @@ bool lgCanSetProcessTitle(void)
 
 void lgSetProcessTitle(const char * title)
 {
+  (void)title;
+
   // not implemented on Windows
 }
diff --git a/common/src/platform/windows/win32.c b/common/src/platform/windows/win32.c
new file mode 100644
index 00000000..1ac5c9a4
--- /dev/null
+++ b/common/src/platform/windows/win32.c
@@ -0,0 +1,72 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "common/win32.h"
+
+#include <stdlib.h>
+#include <windows.h>
+
+wchar_t * lgUtf8ToWide(const char * input)
+{
+  if (!input)
+    return NULL;
+
+  const int length = MultiByteToWideChar(
+      CP_UTF8, MB_ERR_INVALID_CHARS, input, -1, NULL, 0);
+  if (!length)
+    return NULL;
+
+  wchar_t * output = malloc((size_t)length * sizeof(*output));
+  if (!output)
+    return NULL;
+
+  if (!MultiByteToWideChar(
+        CP_UTF8, MB_ERR_INVALID_CHARS, input, -1, output, length))
+  {
+    free(output);
+    return NULL;
+  }
+
+  return output;
+}
+
+char * lgWideToUtf8(const wchar_t * input)
+{
+  if (!input)
+    return NULL;
+
+  const int length = WideCharToMultiByte(
+      CP_UTF8, WC_ERR_INVALID_CHARS, input, -1, NULL, 0, NULL, NULL);
+  if (!length)
+    return NULL;
+
+  char * output = malloc((size_t)length);
+  if (!output)
+    return NULL;
+
+  if (!WideCharToMultiByte(CP_UTF8, WC_ERR_INVALID_CHARS,
+        input, -1, output, length, NULL, NULL))
+  {
+    free(output);
+    return NULL;
+  }
+
+  return output;
+}