For example it is required to change the default backup location to D:\Plesk\Backup:
1. Moved C:\Program Files (x86)\Parallels\Plesk\Backup directory to D:\Plesk\Backup;
2. Set HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\PLESK\PSA Config\Config\DUMP_D" registry value to "D:\Plesk\Backup"
Please, see the following article for more information: