The problem is, when I try to download the pre-alpha for windows, my antivirus will not let me download the zip file because it says the file is infected. Please get the file uninfected.
I think your antivirus software is mistaken. I just downloaded a fresh copy and scanned it and found no issues. Furthermore, it ran fine.
Just to be sure, you are downloading it from here, right?
http://mythruna.com/download-now/