diff --git a/file_windows.go b/file_windows.go
index 9123564..4dc2a2c 100644
--- a/file_windows.go
+++ b/file_windows.go
@@ -327,10 +327,10 @@ func initDirNameExt(filename string, name []uint16) (dir *uint16, ext *uint16) {
 		copy(name, syscall.StringToUTF16(n))
 	}
 	if d != "" {
-		dir = strptr(d)
+		dir = syscall.StringToUTF16Ptr(d)
 	}
 	if len(e) > 1 {
-		ext = strptr(e[1:])
+		ext = syscall.StringToUTF16Ptr(e[1:])
 	}
 	return
 }
diff --git a/internal/win/comdlg32.go b/internal/win/comdlg32.go
index fb1cf53..f8d5578 100644
--- a/internal/win/comdlg32.go
+++ b/internal/win/comdlg32.go
@@ -71,7 +71,7 @@ func CommDlgError() error {
 	if code := commDlgExtendedError(); code == 0 {
 		return zenutil.ErrCanceled
 	} else {
-		return fmt.Errorf("Common Dialog error: %x", code)
+		return fmt.Errorf("common dialog error: %x", code)
 	}
 }
 
diff --git a/internal/win/kernel32.go b/internal/win/kernel32.go
index f495f2d..04005ed 100644
--- a/internal/win/kernel32.go
+++ b/internal/win/kernel32.go
@@ -15,11 +15,11 @@ const (
 	ACTCTX_FLAG_HMODULE_VALID                = 0x080
 
 	// Control signals
-	CTRL_C_EVENT        = 0
-	CTRL_BREAK_EVENT    = 1
-	CTRL_CLOSE_EVENT    = 2
-	CTRL_LOGOFF_EVENT   = 5
-	CTRL_SHUTDOWN_EVENT = 6
+	CTRL_C_EVENT        = windows.CTRL_C_EVENT
+	CTRL_BREAK_EVENT    = windows.CTRL_BREAK_EVENT
+	CTRL_CLOSE_EVENT    = windows.CTRL_CLOSE_EVENT
+	CTRL_LOGOFF_EVENT   = windows.CTRL_LOGOFF_EVENT
+	CTRL_SHUTDOWN_EVENT = windows.CTRL_SHUTDOWN_EVENT
 )
 
 // https://docs.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-actctxw
@@ -37,11 +37,13 @@ type ACTCTX struct {
 
 func GetCurrentThreadId() (id uint32)     { return windows.GetCurrentThreadId() }
 func GetSystemDirectory() (string, error) { return windows.GetSystemDirectory() }
+func GenerateConsoleCtrlEvent(ctrlEvent uint32, processGroupID uint32) (err error) {
+	return windows.GenerateConsoleCtrlEvent(ctrlEvent, processGroupID)
+}
 
 //sys ActivateActCtx(actCtx Handle, cookie *uintptr) (err error)
 //sys CreateActCtx(actCtx *ACTCTX) (ret Handle, err error) [failretval==^Handle(0)] = CreateActCtxW
 //sys DeactivateActCtx(flags uint32, cookie uintptr) (err error)
-//sys GenerateConsoleCtrlEvent(ctrlEvent uint32, processGroupId int) (err error)
 //sys GetConsoleWindow() (ret HWND)
 //sys GetModuleHandle(moduleName *uint16) (ret Handle, err error) = GetModuleHandleW
 //sys GlobalAlloc(flags uint32, bytes uintptr) (ret Handle, err error)
diff --git a/internal/win/ole32.go b/internal/win/ole32.go
index 5850a10..6f48e37 100644
--- a/internal/win/ole32.go
+++ b/internal/win/ole32.go
@@ -62,8 +62,8 @@ func unkcall(self, trap uintptr, a ...uintptr) (r1, r2 uintptr, lastErr error) {
 
 type IBindCtx struct{ IUnknown }
 
-//sys CoCreateInstance(clsid uintptr, unkOuter *IUnknown, clsContext int32, iid uintptr, address unsafe.Pointer) (res error) = ole32.CoCreateInstance
+//sys CoCreateInstance(clsid *GUID, unkOuter *IUnknown, clsContext int32, iid *GUID, address unsafe.Pointer) (res error) = ole32.CoCreateInstance
 
-func uuid(s string) uintptr {
-	return (*reflect.StringHeader)(unsafe.Pointer(&s)).Data
+func guid(s string) *GUID {
+	return (*GUID)(unsafe.Pointer((*reflect.StringHeader)(unsafe.Pointer(&s)).Data))
 }
diff --git a/internal/win/shell32.go b/internal/win/shell32.go
index be88997..ccfa0f0 100644
--- a/internal/win/shell32.go
+++ b/internal/win/shell32.go
@@ -3,9 +3,10 @@
 package win
 
 import (
-	"reflect"
 	"syscall"
 	"unsafe"
+
+	"golang.org/x/sys/windows"
 )
 
 const (
@@ -120,9 +121,9 @@ type IDLIST struct{}
 // https://github.com/wine-mirror/wine/blob/master/include/shobjidl.idl
 
 var (
-	IID_IShellItem       = uuid("\x1e\x6d\x82\x43\x18\xe7\xee\x42\xbc\x55\xa1\xe2\x61\xc3\x7b\xfe")
-	IID_IFileOpenDialog  = uuid("\x88\x72\x7c\xd5\xad\xd4\x68\x47\xbe\x02\x9d\x96\x95\x32\xd9\x60")
-	CLSID_FileOpenDialog = uuid("\x9c\x5a\x1c\xdc\x8a\xe8\xde\x4d\xa5\xa1\x60\xf8\x2a\x20\xae\xf7")
+	IID_IShellItem       = guid("\x1e\x6d\x82\x43\x18\xe7\xee\x42\xbc\x55\xa1\xe2\x61\xc3\x7b\xfe")
+	IID_IFileOpenDialog  = guid("\x88\x72\x7c\xd5\xad\xd4\x68\x47\xbe\x02\x9d\x96\x95\x32\xd9\x60")
+	CLSID_FileOpenDialog = guid("\x9c\x5a\x1c\xdc\x8a\xe8\xde\x4d\xa5\xa1\x60\xf8\x2a\x20\xae\xf7")
 )
 
 type IFileOpenDialog struct{ IFileDialog }
@@ -240,16 +241,14 @@ type iShellItemVtbl struct {
 }
 
 func (u *IShellItem) GetDisplayName(name int) (res string, err error) {
-	var ptr uintptr
+	var ptr *uint16
 	vtbl := *(**iShellItemVtbl)(unsafe.Pointer(u))
 	hr, _, _ := u.call(vtbl.GetDisplayName, uintptr(name), uintptr(unsafe.Pointer(&ptr)))
 	if hr != 0 {
 		err = syscall.Errno(hr)
 	} else {
-		var buf []uint16
-		hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf))
-		hdr.Data, hdr.Len, hdr.Cap = uintptr(ptr), 32768, 32768
-		res = syscall.UTF16ToString(buf)
+		res = windows.UTF16PtrToString(ptr)
+		CoTaskMemFree(unsafe.Pointer(ptr))
 	}
 	return
 }
@@ -286,6 +285,6 @@ func (u *IShellItemArray) GetItemAt(index uint32) (item *IShellItem, err error)
 
 //sys ExtractAssociatedIcon(instance Handle, path *uint16, icon *uint16) (ret Handle, err error) = shell32.ExtractAssociatedIconW
 //sys SHBrowseForFolder(bi *BROWSEINFO) (ret *IDLIST) = shell32.SHBrowseForFolder
-//sys SHCreateItemFromParsingName(path *uint16, bc *IBindCtx, iid uintptr, item **IShellItem) (res error) = shell32.SHCreateItemFromParsingName
+//sys SHCreateItemFromParsingName(path *uint16, bc *IBindCtx, iid *GUID, item **IShellItem) (res error) = shell32.SHCreateItemFromParsingName
 //sys ShellNotifyIcon(message uint32, data *NOTIFYICONDATA) (ok bool) = shell32.Shell_NotifyIconW
 //sys SHGetPathFromIDListEx(ptr *IDLIST, path *uint16, pathLen int, opts int) (ok bool) = shell32.SHGetPathFromIDListEx
diff --git a/internal/win/user32.go b/internal/win/user32.go
index 3957784..bfd1369 100644
--- a/internal/win/user32.go
+++ b/internal/win/user32.go
@@ -265,9 +265,12 @@ func GetWindowThreadProcessId(hwnd HWND, pid *uint32) (tid uint32, err error) {
 
 func GetWindowText(wnd HWND) string {
 	len, _ := getWindowTextLength(wnd)
+	if len == 0 {
+		return ""
+	}
 	buf := make([]uint16, len+1)
 	getWindowText(wnd, &buf[0], len+1)
-	return syscall.UTF16ToString(buf)
+	return windows.UTF16ToString(buf)
 }
 
 func SendMessagePointer(wnd HWND, msg uint32, wparam uintptr, lparam unsafe.Pointer) (ret uintptr) {
diff --git a/internal/win/win32.go b/internal/win/win32.go
index b026bd4..35aa2be 100644
--- a/internal/win/win32.go
+++ b/internal/win/win32.go
@@ -5,9 +5,12 @@ package win
 
 import "golang.org/x/sys/windows"
 
-type Handle = windows.Handle
-type HWND = windows.HWND
-type Pointer = windows.Pointer
+type (
+	Handle  = windows.Handle
+	HWND    = windows.HWND
+	Pointer = windows.Pointer
+	GUID    = windows.GUID
+)
 
 // https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-systemtime
 type SYSTEMTIME struct {
diff --git a/internal/win/zsyscall_windows.go b/internal/win/zsyscall_windows.go
index 2716faa..d5f6d8e 100644
--- a/internal/win/zsyscall_windows.go
+++ b/internal/win/zsyscall_windows.go
@@ -58,7 +58,6 @@ var (
 	procActivateActCtx               = modkernel32.NewProc("ActivateActCtx")
 	procCreateActCtxW                = modkernel32.NewProc("CreateActCtxW")
 	procDeactivateActCtx             = modkernel32.NewProc("DeactivateActCtx")
-	procGenerateConsoleCtrlEvent     = modkernel32.NewProc("GenerateConsoleCtrlEvent")
 	procGetConsoleWindow             = modkernel32.NewProc("GetConsoleWindow")
 	procGetModuleHandleW             = modkernel32.NewProc("GetModuleHandleW")
 	procGlobalAlloc                  = modkernel32.NewProc("GlobalAlloc")
@@ -182,14 +181,6 @@ func DeactivateActCtx(flags uint32, cookie uintptr) (err error) {
 	return
 }
 
-func GenerateConsoleCtrlEvent(ctrlEvent uint32, processGroupId int) (err error) {
-	r1, _, e1 := syscall.Syscall(procGenerateConsoleCtrlEvent.Addr(), 2, uintptr(ctrlEvent), uintptr(processGroupId), 0)
-	if r1 == 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
 func GetConsoleWindow() (ret HWND) {
 	r0, _, _ := syscall.Syscall(procGetConsoleWindow.Addr(), 0, 0, 0, 0)
 	ret = HWND(r0)
@@ -227,8 +218,8 @@ func ReleaseActCtx(actCtx Handle) {
 	return
 }
 
-func CoCreateInstance(clsid uintptr, unkOuter *IUnknown, clsContext int32, iid uintptr, address unsafe.Pointer) (res error) {
-	r0, _, _ := syscall.Syscall6(procCoCreateInstance.Addr(), 5, uintptr(clsid), uintptr(unsafe.Pointer(unkOuter)), uintptr(clsContext), uintptr(iid), uintptr(address), 0)
+func CoCreateInstance(clsid *GUID, unkOuter *IUnknown, clsContext int32, iid *GUID, address unsafe.Pointer) (res error) {
+	r0, _, _ := syscall.Syscall6(procCoCreateInstance.Addr(), 5, uintptr(unsafe.Pointer(clsid)), uintptr(unsafe.Pointer(unkOuter)), uintptr(clsContext), uintptr(unsafe.Pointer(iid)), uintptr(address), 0)
 	if r0 != 0 {
 		res = syscall.Errno(r0)
 	}
@@ -250,8 +241,8 @@ func SHBrowseForFolder(bi *BROWSEINFO) (ret *IDLIST) {
 	return
 }
 
-func SHCreateItemFromParsingName(path *uint16, bc *IBindCtx, iid uintptr, item **IShellItem) (res error) {
-	r0, _, _ := syscall.Syscall6(procSHCreateItemFromParsingName.Addr(), 4, uintptr(unsafe.Pointer(path)), uintptr(unsafe.Pointer(bc)), uintptr(iid), uintptr(unsafe.Pointer(item)), 0, 0)
+func SHCreateItemFromParsingName(path *uint16, bc *IBindCtx, iid *GUID, item **IShellItem) (res error) {
+	r0, _, _ := syscall.Syscall6(procSHCreateItemFromParsingName.Addr(), 4, uintptr(unsafe.Pointer(path)), uintptr(unsafe.Pointer(bc)), uintptr(unsafe.Pointer(iid)), uintptr(unsafe.Pointer(item)), 0, 0)
 	if r0 != 0 {
 		res = syscall.Errno(r0)
 	}