Hi aram and welcome to TG. Sorry to hear you're having issues with installing Xara Designer ProX 12.
Unfortunately I can only suggest unistalling Xara, deleting the original download installer and starting afresh, by re-downloading the installer, and trying a reinstall. If you're still having problems, it may be something to do with your Firewall or AV.
If you still can't get a good install contact Xara Support:
http://support.xara.com/
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