diff --git a/device/win_usb/win_usb.cpp b/device/win_usb/win_usb.cpp
index 7a73369..8bdc277 100644
--- a/device/win_usb/win_usb.cpp
+++ b/device/win_usb/win_usb.cpp
@@ -76,6 +76,20 @@ std::wstring ansi2unicode(const char* ansi, UINT cp = CP_ACP)
 
     return unic;
 }
+std::string unicode2ansi(const wchar_t* unic, UINT cp = CP_ACP)
+{
+    int     len = WideCharToMultiByte(cp, 0, unic, lstrlenW(unic), NULL, 0, NULL, NULL);
+    char    *buf = new char[len + 4];
+
+    memset(buf, 0, len + 4);
+    len = WideCharToMultiByte(cp, 0, unic, lstrlenW(unic), buf, len, NULL, NULL);
+    buf[len--] = 0;
+
+    std::string ansi(buf);
+    delete[] buf;
+
+    return ansi;
+}
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // OVERLAPPED ...
 ovl_cls::ovl_cls() : ref_(1), io_bytes_(0)
@@ -377,6 +391,16 @@ bool usb_device::init(void)
             COPY_MEMBER(dev_desc_, &info->ConnectionInfo->DeviceDescriptor, iSerialNumber);
             COPY_MEMBER(dev_desc_, &info->ConnectionInfo->DeviceDescriptor, bNumConfigurations);
         }
+        PSTRING_DESCRIPTOR_NODE strdesc = info->StringDescs;
+        while (strdesc)
+        {
+            STRCFG  sc;
+            sc.id = strdesc->DescriptorIndex;
+            sc.val = strdesc->StringDescriptor ? unicode2ansi(strdesc->StringDescriptor->bString) : "";
+            str_cfg_.push_back(sc);
+
+            strdesc = strdesc->Next;
+        }
         if (info->ConfigDesc)
         {
             libusb_config_descriptor* desc = NULL;
@@ -459,6 +483,7 @@ void usb_device::clear(void)
 {
     close();
 
+    str_cfg_.clear();
     if (dev_desc_)
         delete dev_desc_;
     dev_desc_ = NULL;
@@ -524,6 +549,23 @@ int usb_device::get_config_descriptor(int index, libusb_config_descriptor** desc
 
     return LIBUSB_SUCCESS;
 }
+int usb_device::get_config_string(uint8_t desc_index, unsigned char* data, int length)
+{
+    for (auto& v : str_cfg_)
+    {
+        if (v.id == desc_index)
+        {
+            if (length < v.val.length())
+                memcpy(data, v.val.c_str(), length);
+            else
+                strcpy((char*)data, v.val.c_str());
+
+            return LIBUSB_SUCCESS;
+        }
+    }
+
+    return LIBUSB_ERROR_NOT_FOUND;
+}
 int usb_device::open(libusb_device_handle** dev_handle)
 {
     if (handle_)
@@ -1475,4 +1517,9 @@ uint8_t LIBUSB_CALL libusb_get_device_address(libusb_device* device)
 
     return ((usb_device*)device)->address();
 }
+int LIBUSB_CALL libusb_get_string_descriptor_ascii(libusb_device_handle* dev_handle,
+    uint8_t desc_index, unsigned char* data, int length)
+{
+    return ((usb_device*)dev_handle)->get_config_string(desc_index, data, length);
+}
 
diff --git a/device/win_usb/win_usb.h b/device/win_usb/win_usb.h
index 1a3f3e9..564d13c 100644
--- a/device/win_usb/win_usb.h
+++ b/device/win_usb/win_usb.h
@@ -100,6 +100,13 @@ class usb_device	//	consider as libusb_device
 	libusb_device_descriptor* dev_desc_;
 	std::vector<libusb_config_descriptor*>	cfg_desc_;
 
+	typedef struct _str_cfg
+	{
+		int			id;
+		std::string	val;
+	}STRCFG;
+	std::vector<STRCFG>	str_cfg_;
+
 	typedef struct _usb_pipe
 	{
 		UCHAR	address;
@@ -145,6 +152,7 @@ public:
 	void clear(void);
 	int get_descriptor(libusb_device_descriptor* desc);
 	int get_config_descriptor(int index, libusb_config_descriptor** desc);
+	int get_config_string(uint8_t desc_index, unsigned char* data, int length);
 	int open(libusb_device_handle** dev_handle);
 	int close(void);
 	int set_timeout(unsigned milliseconds);
diff --git a/sane/scanner.cpp b/sane/scanner.cpp
index fcc0c02..09b5ea7 100644
--- a/sane/scanner.cpp
+++ b/sane/scanner.cpp
@@ -2810,8 +2810,8 @@ COM_API_IMPLEMENT(scanner, int, start(void))
 		thread_starting_->join();
 #ifdef START_SCAN_IN_THREAD
 	thread_starting_.reset(new std::thread(&scanner::thread_start, this));
-	get_scanned_images(-1);	// block until image arrived or scan finished
-	ret = err_;
+	ret = get_scanned_images(-1);	// block until image arrived or scan finished
+	ret = ret > 0 ? 0 : err_;		// received images, ensure return success. BUG-809
 #else
 	ret = thread_start();
 #endif