Click and paste the path to your extracted folder (e.g., C:\UPX ). Click OK on all windows to save. Step 3: Verify the Installation To make sure everything is working:

The most reliable way to get UPX is from its official repository. While third-party sites like Softonic or Uptodown host it, the official source ensures you have the latest, untampered version.

Look for the latest release (currently v5.1.1 as of early 2026). Choose upx-5.1.1-win64.zip for 64-bit systems. Choose upx-5.1.1-win32.zip for older 32-bit systems.

UPX replaces the original file with the compressed version, so before you start. UPX: the Ultimate Packer for eXecutables - Homepage