It may help if you post what changes you made in the httpd-vhost.conf file as any errors in this file will have disasterous consequences.
The error message tells you what is amiss here.
You don't have permission to access the requested directory. There is either no index document or the directory is read-protected.
Check you directory paths in the httpd-vhosts.conf
are indeed correct then double check them
then make sure that an index file, index.html or index.php etc. is present in those indicated virtual host web root directories.
Also check the permissions or in Windows they call them Properties
is not set to read-only. change them and re-start Apache. Always restart Apache when you make changes in any of the .conf files in the Apache conf directory or it won't know of the changes you have made.
Should be no need to re-install because if the httpd-vhosts.conf is incorrect or as indicated by the error message there is no index file or permissions are incorect then you will only get the same result.
If it's any help I installed zpanel on a test domain and it creates accounts and functions as it should with no problems in XAMPP. Make sure all the paths in the zpanel configuration point to the correct places within the XAMPP tree.