diff --git a/appveyor.yml b/appveyor.yml
index ce0976c..a54864b 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -9,6 +9,8 @@ environment:
   GITHUB_TOKEN:
     secure: 3wuEGJsppSKFvdwhp3jprUA9Zkc3WINlc/9oFXjhAR6J05lYMXP7Fl7lXTKpkGZx
 install:
+  - rmdir C:\cygwin /s /q
+  - rmdir C:\QT /s /q
   - ps: Install-Product node 8
   - curl -L -o nasm.exe https://www.nasm.us/pub/nasm/releasebuilds/2.13.03/win64/nasm-2.13.03-installer-x64.exe
   - start /wait nasm.exe /S