fix download file name.
diff --git a/update_build_tools.py b/update_build_tools.py
index 671ce14..2f219c3 100755
--- a/update_build_tools.py
+++ b/update_build_tools.py
@@ -79,7 +79,7 @@
     listing = os.listdir(args.localDir)
 
 
-buildToolsZipRE = re.compile(r'^sdk-repo-linux-build-tools-.*\.zip$')
+buildToolsZipRE = re.compile(r'^sdk-repo-windows-build-tools-.*\.zip$')
 buildToolsZipFile = None
 for fname in listing:
     if buildToolsZipRE.match(fname):