diff --git a/chardev/char-pipe.c b/chardev/char-pipe.c
index 94d714ffcd..fd12c9e63b 100644
--- a/chardev/char-pipe.c
+++ b/chardev/char-pipe.c
@@ -70,7 +70,7 @@ static int win_chr_pipe_init(Chardev *chr, const char *filename,
                               MAXCONNECT, NSENDBUF, NRECVBUF, NTIMEOUT, NULL);
     g_free(openname);
     if (s->file == INVALID_HANDLE_VALUE) {
-        error_setg(errp, "Failed CreateNamedPipe (%lu)", GetLastError());
+        error_setg_win32(errp, GetLastError(), "Failed CreateNamedPipe");
         s->file = NULL;
         goto fail;
     }
diff --git a/chardev/char-win.c b/chardev/char-win.c
index 34825f683d..d4fb44c4dc 100644
--- a/chardev/char-win.c
+++ b/chardev/char-win.c
@@ -96,7 +96,7 @@ int win_chr_serial_init(Chardev *chr, const char *filename, Error **errp)
     s->file = CreateFile(filename, GENERIC_READ | GENERIC_WRITE, 0, NULL,
                       OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
     if (s->file == INVALID_HANDLE_VALUE) {
-        error_setg(errp, "Failed CreateFile (%lu)", GetLastError());
+        error_setg_win32(errp, GetLastError(), "Failed CreateFile");
         s->file = NULL;
         goto fail;
     }
diff --git a/qga/channel-win32.c b/qga/channel-win32.c
index c86f4388db..4f04868a76 100644
--- a/qga/channel-win32.c
+++ b/qga/channel-win32.c
@@ -302,13 +302,14 @@ static gboolean ga_channel_open(GAChannel *c, GAChannelMethod method,
                            OPEN_EXISTING,
                            FILE_FLAG_NO_BUFFERING | FILE_FLAG_OVERLAPPED, NULL);
     if (c->handle == INVALID_HANDLE_VALUE) {
-        g_critical("error opening path %s: %s", newpath,
-                   g_win32_error_message(GetLastError()));
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        g_critical("error opening path %s: %s", newpath, emsg);
         return false;
     }
 
     if (method == GA_CHANNEL_ISA_SERIAL && !SetCommTimeouts(c->handle,&comTimeOut)) {
-        g_critical("error setting timeout for com port: %lu",GetLastError());
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        g_critical("error setting timeout for com port: %s", emsg);
         CloseHandle(c->handle);
         return false;
     }
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 2461fd19bf..9c744d6405 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -315,8 +315,9 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **errp)
     }
 
     if (!ExitWindowsEx(shutdown_flag, SHTDN_REASON_FLAG_PLANNED)) {
-        slog("guest-shutdown failed: %lu", GetLastError());
-        error_setg(errp, QERR_UNDEFINED_ERROR);
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        slog("guest-shutdown failed: %s", emsg);
+        error_setg_win32(errp, GetLastError(), "guest-shutdown failed");
     }
 }
 
@@ -1319,7 +1320,8 @@ static DWORD WINAPI do_suspend(LPVOID opaque)
     DWORD ret = 0;
 
     if (!SetSuspendState(*mode == GUEST_SUSPEND_MODE_DISK, TRUE, TRUE)) {
-        slog("failed to suspend guest, %lu", GetLastError());
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        slog("failed to suspend guest: %s", emsg);
         ret = -1;
     }
     g_free(mode);
diff --git a/util/osdep.c b/util/osdep.c
index f7d06050f7..4829c07ff6 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -82,8 +82,8 @@ static int qemu_mprotect__osdep(void *addr, size_t size, int prot)
     DWORD old_protect;
 
     if (!VirtualProtect(addr, size, prot, &old_protect)) {
-        error_report("%s: VirtualProtect failed with error code %ld",
-                     __func__, GetLastError());
+        g_autofree gchar *emsg = g_win32_error_message(GetLastError());
+        error_report("%s: VirtualProtect failed: %s", __func__, emsg);
         return -1;
     }
     return 0;