diff --git a/client/installer.nsis b/client/installer.nsis
index 7dbd21ad9..b92cb9bc1 100644
--- a/client/installer.nsis
+++ b/client/installer.nsis
@@ -15,6 +15,13 @@
 !define REG_ROOT "HKLM"
 !define REG_APP_PATH "Software\Microsoft\Windows\CurrentVersion\App Paths\${MAIN_APP_EXE}"
 !define UNINSTALL_PATH "Software\Microsoft\Windows\CurrentVersion\Uninstall\${APP_NAME}"
+
+!define UI_APP_NAME "Wiretrustee UI"
+!define UI_APP_EXE "Wiretrustee-ui"
+
+!define UI_REG_APP_PATH "Software\Microsoft\Windows\CurrentVersion\App Paths\${UI_APP_EXE}"
+!define UI_UNINSTALL_PATH "Software\Microsoft\Windows\CurrentVersion\Uninstall\${UI_APP_NAME}"
+
 Unicode True
 
 ######################################################################
@@ -77,6 +84,7 @@ Section -MainProgram
 	SetOverwrite ifnewer
 	SetOutPath "$INSTDIR"
 	File /r "..\\dist\\wiretrustee_windows_amd64\\"
+	File /r "..\\dist\\wiretrustee-ui_windows_amd64\\"
 
 SectionEnd
 
@@ -93,6 +101,13 @@ WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "DisplayIcon" "$INSTDIR\${MAIN_APP_
 WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "DisplayVersion" "${VERSION}"
 WriteRegStr ${REG_ROOT} "${UNINSTALL_PATH}"  "Publisher" "${COMP_NAME}"
 
+WriteRegStr ${REG_ROOT} "${UI_REG_APP_PATH}" "" "$INSTDIR\${UI_APP_EXE}"
+WriteRegStr ${REG_ROOT} "${UI_UNINSTALL_PATH}"  "DisplayName" "${UI_APP_NAME}"
+WriteRegStr ${REG_ROOT} "${UI_UNINSTALL_PATH}"  "UninstallString" "$INSTDIR\wiretrustee_uninstall.exe"
+WriteRegStr ${REG_ROOT} "${UI_UNINSTALL_PATH}"  "DisplayIcon" "$INSTDIR\${UI_APP_EXE}"
+WriteRegStr ${REG_ROOT} "${UI_UNINSTALL_PATH}"  "DisplayVersion" "${VERSION}"
+WriteRegStr ${REG_ROOT} "${UI_UNINSTALL_PATH}"  "Publisher" "${COMP_NAME}"
+
 EnVar::SetHKLM
 EnVar::AddValueEx "path" "$INSTDIR"
 
@@ -117,4 +132,4 @@ DeleteRegKey ${REG_ROOT} "${REG_APP_PATH}"
 DeleteRegKey ${REG_ROOT} "${UNINSTALL_PATH}"
 EnVar::SetHKLM
 EnVar::DeleteValue "path" "$INSTDIR"
-SectionEnd
\ No newline at end of file
+SectionEnd
diff --git a/client/ui/client_ui.go b/client/ui/client_ui.go
index d72663d16..6d8cff76f 100644
--- a/client/ui/client_ui.go
+++ b/client/ui/client_ui.go
@@ -4,8 +4,13 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
 	"runtime"
+	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	_ "embed"
@@ -22,6 +27,11 @@ import (
 func main() {
 	var daemonAddr string
 
+	if err := checkPIDFile(); err != nil {
+		fmt.Println(err)
+		return
+	}
+
 	defaultDaemonAddr := "unix:///var/run/wiretrustee.sock"
 	if runtime.GOOS == "windows" {
 		defaultDaemonAddr = "tcp://127.0.0.1:41731"
@@ -214,3 +224,19 @@ func (s *serviceClient) client() (proto.DaemonServiceClient, error) {
 	s.conn = proto.NewDaemonServiceClient(conn)
 	return s.conn, nil
 }
+
+// checkPIDFile exists and return error, or write new.
+func checkPIDFile() error {
+	pidFile := path.Join(os.TempDir(), "wiretrustee-ui.pid")
+	if piddata, err := ioutil.ReadFile(pidFile); err == nil {
+		if pid, err := strconv.Atoi(string(piddata)); err == nil {
+			if process, err := os.FindProcess(pid); err == nil {
+				if err := process.Signal(syscall.Signal(0)); err == nil {
+					return fmt.Errorf("process already exists: %d", pid)
+				}
+			}
+		}
+	}
+
+	return ioutil.WriteFile(pidFile, []byte(fmt.Sprintf("%d", os.Getpid())), 0o664)
+}