This is most probably due to poor internet connection. What may have happened is, during the download process the internet got disconnected. So you will need to re-download. Sometimes, even after re-download the file says corrupted. This is due to browser caching.
This is how to fix this:
- Delete the corrupted file (LSEnt70.exe etc.) that you downloaded.
- Or, save with a new file name like LSEnt70-New.exe etc.
- After download is complete, go to where you saved the file, then double-click on it to start the installation.