nmbro · Oct 19, 2026 · Oct 19, 2026 · Oct 19, 2026 · Oct 19, 2026 · Oct 20, 2026
diff --git a/.github/scripts/appveyor/02-install.bat b/.github/scripts/appveyor/02-install.bat
@@ -31,7 +31,7 @@ REM Without the ecosystem update above, the overhead of this step remained
 REM similar. It did however use a smaller population (via deps) and older
 REM versions of packages.
 REM Prerequisites for NUT per https://github.com/networkupstools/nut/blob/master/docs/config-prereqs.txt :
-C:\msys64\usr\bin\bash -lc "date -u; pacman --noconfirm -S --needed base-devel mingw-w64-x86_64-toolchain autoconf-wrapper automake-wrapper libtool mingw-w64-x86_64-libltdl gcc ccache mingw-w64-x86_64-ccache git aspell aspell-en python mingw-w64-x86_64-python-pygments mingw-w64-x86_64-winpthreads-git mingw-w64-x86_64-libusb mingw-w64-x86_64-libusb-compat-git mingw-w64-x86_64-neon libneon-devel mingw-w64-x86_64-libgd mingw-w64-x86_64-cppunit mingw-w64-x86_64-nss mingw-w64-x86_64-openssl"
+C:\msys64\usr\bin\bash -lc "date -u; pacman --noconfirm -S --needed base-devel mingw-w64-x86_64-toolchain autoconf-wrapper automake-wrapper libtool mingw-w64-x86_64-libltdl gcc ccache mingw-w64-x86_64-ccache git aspell aspell-en python mingw-w64-x86_64-python-pygments mingw-w64-x86_64-winpthreads-git mingw-w64-x86_64-libusb mingw-w64-x86_64-neon libneon-devel mingw-w64-x86_64-libgd mingw-w64-x86_64-cppunit mingw-w64-x86_64-nss mingw-w64-x86_64-openssl"
 if errorlevel 1 exit /b %ERRORLEVEL%
 REM SKIP mingw-w64-x86_64-libmodbus-git : we custom-build one with USB support
 REM SKIP for now NUT-Monitor prereqs (runtime Python would require somilar modules; need to fix localization builds like "fr.po"): gettext mingw-w64-x86_64-python-pyqt6

diff --git a/INSTALL.nut.adoc b/INSTALL.nut.adoc
@@ -954,6 +954,18 @@ Archives with binaries built by recent iterations of continuous integration
 jobs should be available for exploration on the respective CI platforms.
 ======
 
+[[Windows_USB]]
+USB-connected devices
+^^^^^^^^^^^^^^^^^^^^^
+
+If you plan to use an UPS which is locally connected to an USB port,
+you have to bind it to the WinUSB driver, so that NUT (built with
+libusb-1.0) can open it. Most UPS devices are bound to the Windows HID
+driver by default. You can use the `wdi-simple` program shipped with NUT
+(see `scripts/Windows/DriverInstaller` in the sources), or
+link:https://zadig.akeo.ie/[Zadig]: select the UPS, choose `WinUSB` and
+click "Replace Driver". Both currently support Windows 7 and newer.
+
 Historical MSI installer
 ^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -973,15 +985,16 @@ Newer Windows releases should include the Windows Installer natively.
 
 Run `NUT-Installer.msi` and follow the wizard indications.
 
-If you plan to use an UPS which is locally connected to an USB port,
-you have to install
-link:https://sourceforge.net/projects/libusb-win32/files/[libUSB-win32]
-on your system. Then you must install your device via libusb's "Inf Wizard".
-
-NOTE: If you intend to build from source, relevant sources may be available at
-https://github.com/mcuee/libusb-win32 and keep in mind that it is a variant of
-libusb-0.1. Current NUT supports libusb-1.0 as well, and that project should
-have Windows support out of the box (but it was not explored for NUT yet).
+That historical package was built with libusb-0.1: to use a locally
+connected USB UPS with it, you would install
+https://github.com/mcuee/libusb-win32[libusb-win32] and bind the device
+to its `libusb0.sys` driver with libusb's "Inf Wizard". Current NUT for
+Windows is built with libusb-1.0 only, and does not support that driver
+(see <<Windows_USB,USB-connected devices>> above instead).
+
+NOTE: A new installer based on the WiX Toolset is being worked on, see
+link:scripts/Windows/Installer/README.adoc[scripts/Windows/Installer/README.adoc]
+and https://github.com/networkupstools/nut/issues/1485 for details.
 
 If you have selected default directory, all configuration files are located in
 `C:\Program Files\NUT\ups\etc`

diff --git a/NEWS.adoc b/NEWS.adoc
@@ -82,6 +82,11 @@ https://github.com/networkupstools/nut/milestone/13
         result was stored as the availability of the XML/HTTP scan. So the
         `-M` scan could be disabled despite a working `libneon`, or offered
         without one (impacts NUT v2.8.3 through v2.8.5). [PR #3657]
+      - `nut-scanner` crashed in USB scans in 32-bit Windows builds: it
+        called the dynamically loaded libusb-1.0 methods as default C
+        functions, but there they use the calling convention of Windows
+        API methods (`LIBUSB_CALL`), so the stack got misaligned (impacts
+        all NUT 2.8.x until now). [PR #3791]
     * USB drivers: fixed an out-of-bounds read of the candidate HID report
       descriptor lengths, which could cause a segmentation fault (regression
       added in NUT v2.8.5 release). [PR #3550]
@@ -1123,6 +1128,32 @@ https://github.com/networkupstools/nut/milestone/13
       under `lib64` (e.g. on CentOS 7) and in directories named by just the
       major and minor version (e.g. `aspell-0.60` for `aspell` 0.60.6.1).
       [issue #2068, PR #3773]
+    * USB support can now be built against libusb-1.0 releases from 1.0.9
+      on, such as the `libusb1` 1.0.9 package of CentOS 6. Before 1.0.16
+      there is no `libusb_strerror()`, so error messages show the name of
+      the libusb error code (from `libusb_error_name()`) instead of its
+      description; before 1.0.10 or so there is no `libusb_get_version()`,
+      so `driver.version.usb` says the version is unknown. `nut-scanner`
+      falls back the same way when the libusb it loads at run time lacks
+      these methods. [issues #509, #3781, PR #3782]
+    * With `--with-usb=auto` (or `yes`), the `configure` script now falls
+      back to an also available libusb-0.1 when the preferred libusb-1.0 is
+      too old for NUT, instead of building without USB drivers. An explicit
+      `--with-usb=libusb-1.0` still fails in that case.
+      [issue #3781, PR #3782]
+    * Windows (MinGW/MSYS2) builds of NUT now support only libusb-1.0 for
+      USB drivers, used with the WinUSB driver. Support for libusb-0.1
+      (libusb-win32 with its `libusb0.sys` driver, or libusb-compat) was
+      removed from Windows builds: `configure --with-usb=libusb-0.1` now
+      fails there, and an auto-detected libusb-0.1 is not used. Tested
+      with `apcmicrolink` and `nut-scanner` on Windows 10.
+      [issue #1507, PR #3791]
+    * The `wdi-simple` USB driver installer for Windows now installs the
+      WinUSB driver (or libusbK, if chosen) instead of `libusb0.sys`,
+      accepts command-line options, and no longer reads past the end of
+      the generated NUT USB device table. Its build instructions were
+      updated for current libwdi.
+      [issue #1507, PR #3791]
 
 
 Release notes for NUT 2.8.5 - what's new since 2.8.4

diff --git a/UPGRADING.adoc b/UPGRADING.adoc
@@ -45,6 +45,13 @@ Changes from 2.8.5 to 2.8.6
   `*.pc` files, packaging recipes and tarball names are not changed.
   [PR #3754 follow-up]
 
+- Windows builds of NUT now support only libusb-1.0; libusb-0.1
+  (libusb-win32 or libusb-compat) is no longer supported there, and
+  `--with-usb=libusb-0.1` fails. Packagers should depend on libusb-1.0
+  instead. USB devices previously bound to the libusb-win32
+  `libusb0.sys` driver must be re-bound to the WinUSB driver (e.g. with
+  the updated `wdi-simple` or with Zadig). [issue #1507, PR #3791]
+
 - The Perl `UPS::Nut` module now decodes NUT quoting and backslash escapes
   in query/list values and `nutauth.conf`, including include paths. Remove
   manual decoding of these returned values and pass literal credentials

diff --git a/docs/config-prereqs.txt b/docs/config-prereqs.txt
@@ -2066,23 +2066,14 @@ export PATH
     mingw-w64-x86_64-winpthreads-git \
     mingw-w64-clang-x86_64-winpthreads-git
 
-# Note that MSYS2 includes libusb-1.0 "natively"
-# The NUT codebase adjustments for Windows might at this moment expect older
-# ecosystem via https://github.com/mcuee/libusb-win32 -- subject to fix then.
+# Note that MSYS2 includes libusb-1.0 "natively"; it is the only libusb
+# supported by NUT on Windows (libusb-win32 and libusb-compat, i.e. the
+# libusb-0.1 API, are not). The UPS must be bound to the WinUSB driver
+# (e.g. with Zadig) for libusb-1.0 to open it.
 :; pacman -S --needed \
     mingw-w64-x86_64-libusb \
     mingw-w64-clang-x86_64-libusb
 
-# Seems that the older libusb-win32 (libusb-0.1) is also available as:
-:; pacman -S --needed \
-    mingw-w64-x86_64-libusb-win32 \
-    mingw-w64-clang-x86_64-libusb-win32
-
-# Alternately there is libusb-compat (libusb-1.0 codebase exposing the older
-# libusb-0.1 API) which SHOULD NOT be installed along with the real libusb-0.1:
-# :; pacman -S --needed mingw-w64-x86_64-libusb-compat-git \
-#        mingw-w64-clang-x86_64-libusb-compat-git
-
 # This also pulls *-devel of several other projects:
 :; pacman -S --needed \
     mingw-w64-x86_64-neon libneon-devel \

diff --git a/docs/nut.dict b/docs/nut.dict
@@ -1,4 +1,4 @@
-personal_ws-1.1 en 3917 utf-8
+personal_ws-1.1 en 3930 utf-8
 AAC
 AAS
 ABI
@@ -1587,6 +1587,7 @@ WALKMODE
 WARNFATAL
 WARNOPT
 WCH
+WDK
 WELI
 WH
 WHAD
@@ -2667,6 +2668,8 @@ libtool
 libupsclient
 libusb
 libusb's
+libusbK
+libusbk
 libusbugen
 libusbx
 libvirt
@@ -2701,6 +2704,7 @@ lm
 lmodbus
 ln
 lnetsnmp
+lntdll
 loadPercentage
 localcalculation
 localhost
@@ -2715,6 +2719,7 @@ login
 logins
 logout
 logrotate
+lole
 lookup
 loopback
 lowbatt
@@ -2723,6 +2728,7 @@ lr
 lregex
 ls
 lsd
+lsetupapi
 lst
 lsusb
 lt
@@ -2731,6 +2737,7 @@ lu
 lua
 lv
 lvo
+lwdi
 lws
 lxc
 lxcbr
@@ -3219,6 +3226,7 @@ reconnection
 recurses
 recursing
 recv
+redistributable
 redistributors
 reentrancy
 refactored
@@ -3396,6 +3404,7 @@ slaveaddr
 slaveid
 slavesync
 slibtool
+sln
 sm
 smartslot
 smartups
@@ -3822,6 +3831,7 @@ waitbeforereconnect
 wakeup
 wc
 wdi
+wdkdir
 webserver
 wf
 wg
@@ -3835,6 +3845,7 @@ wininit
 winnutclient
 winpthreads
 winsymlinks
+winusb
 withGiven
 withdoc
 wix

diff --git a/drivers/blazer_usb.c b/drivers/blazer_usb.c
@@ -37,7 +37,7 @@
 #endif	/* WIN32 */
 
 #define DRIVER_NAME	"Megatec/Q1 protocol USB driver"
-#define DRIVER_VERSION	"0.27"
+#define DRIVER_VERSION	"0.28"
 
 /* driver description structure */
 upsdrv_info_t upsdrv_info = {
@@ -595,14 +595,10 @@ ssize_t blazer_command(const char *cmd, char *buf, size_t buflen)
 		break;
 
 	case LIBUSB_ERROR_TIMEOUT:	/* Connection timed out */
-/* libusb-win32 does not know EPROTO and EOVERFLOW,
- * it only returns EIO for any IO errors */
-#ifndef WIN32
 	case LIBUSB_ERROR_OVERFLOW: /* Value too large for defined data type */
-# if EPROTO && WITH_LIBUSB_0_1
+#if EPROTO && WITH_LIBUSB_0_1
 	case -EPROTO:		/* Protocol error */
-# endif
-#endif	/* !WIN32 */
+#endif
 	default:
 		break;
 	}