I downloaded Mathematica free trial version. But, when I try to install it, I get an error saying that the WinZIP file is corrupted or some multipart error.
Can someone please help? Thank You.
That error indicates the ZIP file that you've downloaded is actually corrupted, therefore the extraction fails to complete. I recommend you disable any download managers that you might have on your PC and download the trial packages using only the browser to avoid file corruption. I've downloaded Mathematica as well and I didn't encounter this error.
Additionally, use 7ZIP or WinRAR to unpack the contents.