iClone 8 and iClone 7 can both be installed on the same computer so that is not the issue.
First thing to check is that you have room on the drive you selected. Not having enough free space can cause this error.
Secondly, try opening "Settings" in the Reallusion Hub and go to the "Installer Location" link to see if the iClone 7 installer is already there. If it is, delete it, and then try to install iClone 7 again. This will force the Hub to download a fresh copy of the installer which will eliminate a corrupt installer as being the problem.
Peter
Forum Administrator
www.reallusion.com