I’m using Unity 5.3.5f1 and I get these error message after every new installation…
Unity 4.7 works fine but the new version is strange.
I tried to change the installation path, run Unity as admin and delete the history of the tool but no method works.
It would be nice, if anybody could help me 
My System:
Win 7/ 64 bit
Even i am having the same issue . I solved it by uninstalling the software and deleting it from windows registry too . we need to delete both unity and unity technologies from windows registry and install it again .
Deleting all folder and registry references and full uninstall/re-install hasn’t helped me - judging by the forums, I am not the only one - help!
if your using a registry editing program to get a full version of a software this can happen i restored my pc removing the program cool edit pro i cracked with a registry edit instead of a crack and i got this error
i downloaded a new version of cool edit without that type of registration
and now everything works fine after the restore if you do not have a restore point to remove the program you know you cracked then you will need to reinstall windows
do not use any programs that will alter your registry cause it can cause major errors in other programs or on your system cheers guys
Still no help for me? Any suggestion would be great