Corrupted executable file:
The setup files are corrupted. Please obtain a new copy of the
Usually the above error message appears when an executable file is missing some of the essential components/libraries that is essential to proceed the installation. It is very common that many files could be corrupted in some of the sites we download our free software. Or it could be a simple incomplete download issue. Try downloading your software from a different site.
If all your downloads stops before completion, then there is definitely something wrong with your browser. Try removing add-ons, external tool bars. There might be some uninvited fellow malwares sitting right there and infecting you. If that doesn't work try re-installing the browser.
Be careful when you install anything on your computer and watch out specially for the free add-ons and tool bars offered, there might be malwares included in that. You could identify them by the weird behaviors such as pop ups and similar advertisements on your browsers no matter which site you visit.
I have avira and do scan without results
If your anti virus does not detect anything, then do not just come to a conclusion that you have no threats. Check if the anti virus software is updated. Every day there are lots of virus signatures are identified and updated in the anti virus database. Make sure that Web Anti-Virus option is enabled in your anti virus software. It will block/not allow the malicious websites or pop ups that can harm your computer.
Clear your temporary/dump internet files from your computer. Perform a full system scan with your updated anti virus. Deal with the threats if you find any. Now try to download the software from the official site. Make sure the entire file is downloaded and then proceed with the installation. Your installation should be working fine by now.