I am using the Paragon Hard Disk Manager Suite, trial version I scheduled a full backup to run weekly and ran it successfully, using Paragon's "Run Now" option. Then I scheduled a daily differential backup. But to test it quickly, I used the Paragon's "Run Now" option instead of waiting for the Windows Task Scheduler to launch it later. This worked fine, creating a sub-directory containing the first diff backup files. To further test the diff backup task, I again used Paragon's "Run Now" option, but this time the diff backup exited immediately, doing nothing. (I think using Paragon's "Run Now" is equivalent to waiting for the Windows Task Scheduler to launch it, because I also tried using the "Run" function directly in the windows tool, with the same results.) A few experiments showed that it's the presence of the sub-directory created by the first diff backup that causes problems for the second diff backup. (If I rename the sub-directory after the first diff backup, then the second diff backup runs fine (re-creating the sub-directory). It seems to me that a daily Paragon diff backup needs to run unattended, placing new diff backups in the same sub-directory created by the first diff backup run. Hopefully I'm missing something easy. Thanks.