diff --git a/handler/convertor_windows.go b/handler/convertor_windows.go
index 9ea6702..0f4594b 100644
--- a/handler/convertor_windows.go
+++ b/handler/convertor_windows.go
@@ -42,7 +42,7 @@ func (h ConvertorHandler) downloadFFmpeg(progressBar *widget.ProgressBar, progre
 		MessageID: "unzipRun",
 	})
 	progressMessage.Refresh()
-	err = unZip("ffmpeg/ffmpeg.zip", "ffmpeg")
+	err = unZip("ffmpeg/ffmpeg.zip", "ffmpeg", progressBar)
 	if err != nil {
 		return err
 	}
@@ -100,13 +100,23 @@ func downloadFile(filepath string, url string, progressBar *widget.ProgressBar)
 	return nil
 }
 
-func unZip(fileZip string, directory string) error {
+func unZip(fileZip string, directory string, progressBar *widget.ProgressBar) error {
+	progressBar.Value = 0
+	progressBar.Max = 100
+
 	archive, err := zip.OpenReader(fileZip)
 	if err != nil {
 		return err
 	}
 	defer archive.Close()
 
+	totalBytes := int64(0)
+	for _, f := range archive.File {
+		totalBytes += int64(f.UncompressedSize64)
+	}
+
+	unpackedBytes := int64(0)
+
 	for _, f := range archive.File {
 		filePath := filepath.Join(directory, f.Name)
 
@@ -132,10 +142,15 @@ func unZip(fileZip string, directory string) error {
 			return err
 		}
 
-		if _, err := io.Copy(dstFile, fileInArchive); err != nil {
+		bytesRead, err := io.Copy(dstFile, fileInArchive)
+		if err != nil {
 			return err
 		}
 
+		unpackedBytes += bytesRead
+		progressBar.Value = float64(unpackedBytes) / float64(totalBytes) * 100
+		progressBar.Refresh()
+
 		dstFile.Close()
 		fileInArchive.Close()
 	}