diff --git a/llvm/include/llvm/Support/FileSystem.h b/llvm/include/llvm/Support/FileSystem.h
--- a/llvm/include/llvm/Support/FileSystem.h
+++ b/llvm/include/llvm/Support/FileSystem.h
@@ -865,6 +865,11 @@
   // The open file descriptor.
   int FD = -1;
 
+#ifdef _WIN32
+  // Whether we need to manually remove the file on close.
+  bool RemoveOnClose = false;
+#endif
+
   // Keep this with the given name.
   Error keep(const Twine &Name);
 
diff --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -1188,6 +1188,10 @@
   FD = Other.FD;
   Other.Done = true;
   Other.FD = -1;
+#ifdef _WIN32
+  RemoveOnClose = Other.RemoveOnClose;
+  Other.RemoveOnClose = false;
+#endif
   return *this;
 }
 
@@ -1202,20 +1206,25 @@
   FD = -1;
 
 #ifdef _WIN32
-  // On windows closing will remove the file.
-  TmpName = "";
-  return Error::success();
+  // On Windows, closing will remove the file, if we set the delete
+  // disposition. If not, remove it manually.
+  bool Remove = RemoveOnClose;
 #else
-  // Always try to close and remove.
+  // Always try to remove the file.
+  bool Remove = true;
+#endif
   std::error_code RemoveEC;
-  if (!TmpName.empty()) {
+  if (Remove && !TmpName.empty()) {
     RemoveEC = fs::remove(TmpName);
+#ifndef _WIN32
     sys::DontRemoveFileOnSignal(TmpName);
+#endif
     if (!RemoveEC)
       TmpName = "";
+  } else {
+    TmpName = "";
   }
   return errorCodeToError(RemoveEC);
-#endif
 }
 
 Error TempFile::keep(const Twine &Name) {
@@ -1226,19 +1235,26 @@
   // If we can't cancel the delete don't rename.
   auto H = reinterpret_cast<HANDLE>(_get_osfhandle(FD));
   std::error_code RenameEC = setDeleteDisposition(H, false);
+  bool ShouldDelete = false;
   if (!RenameEC) {
     RenameEC = rename_handle(H, Name);
     // If rename failed because it's cross-device, copy instead
     if (RenameEC ==
       std::error_code(ERROR_NOT_SAME_DEVICE, std::system_category())) {
       RenameEC = copy_file(TmpName, Name);
-      setDeleteDisposition(H, true);
+      ShouldDelete = true;
     }
   }
 
-  // If we can't rename, discard the temporary file.
+  // If we can't rename or copy, discard the temporary file.
   if (RenameEC)
-    setDeleteDisposition(H, true);
+    ShouldDelete = true;
+  if (ShouldDelete) {
+    if (!RemoveOnClose)
+      setDeleteDisposition(H, true);
+    else
+      remove(TmpName);
+  }
 #else
   std::error_code RenameEC = fs::rename(TmpName, Name);
   if (RenameEC) {
@@ -1290,12 +1306,23 @@
                                     OpenFlags ExtraFlags) {
   int FD;
   SmallString<128> ResultPath;
+#ifdef _WIN32
+  sys::fs::createUniquePath(Model, ResultPath, false);
+  StringRef TargetDir = path::parent_path(ResultPath);
+  if (TargetDir.empty())
+    TargetDir = ".";
+  if (is_local(TargetDir))
+    ExtraFlags |= OF_Delete;
+#endif
   if (std::error_code EC =
-          createUniqueFile(Model, FD, ResultPath, OF_Delete | ExtraFlags, Mode))
+          createUniqueFile(Model, FD, ResultPath, ExtraFlags, Mode))
     return errorCodeToError(EC);
 
   TempFile Ret(ResultPath, FD);
-#ifndef _WIN32
+#ifdef _WIN32
+  if (!(ExtraFlags & OF_Delete))
+    Ret.RemoveOnClose = true;
+#else
   if (sys::RemoveFileOnSignal(ResultPath)) {
     // Make sure we delete the file when RemoveFileOnSignal fails.
     consumeError(Ret.discard());
diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -416,8 +416,9 @@
 
   // Check if the file is on a network (non-local) drive. If so, don't
   // continue when DeleteFile is true, since it prevents opening the file for
-  // writes. Note -- this will leak temporary files on disk, but only when the
-  // target file is on a network drive.
+  // writes. This returns an error (instead of silently not doing what was
+  // requested); TempFile::create checks whether the destination is local or
+  // not, and only sets OF_Delete if it's possible (if it's local).
   SmallVector<wchar_t, 128> FinalPath;
   if (std::error_code EC = realPathFromHandle(Handle, FinalPath))
     return EC;
@@ -427,7 +428,7 @@
     return EC;
 
   if (!IsLocal)
-    return std::error_code();
+    return errc::not_supported;
 
   // The file is on a local drive, we can safely set FILE_DISPOSITION_INFO's
   // flag.
@@ -1109,8 +1110,9 @@
   DWORD Result = 0;
   if (Access & FA_Read)
     Result |= GENERIC_READ;
+  // SetFileInformationByHandle(FileRenameInfo) needs DELETE
   if (Access & FA_Write)
-    Result |= GENERIC_WRITE;
+    Result |= GENERIC_WRITE | DELETE;
   if (Flags & OF_Delete)
     Result |= DELETE;
   if (Flags & OF_UpdateAtime)