Following the following steps below can potentially free up available server storage:
1) In File Explorer browse to wherever your company files reside. They will most likely be in one of these two locations:
1 - C:\Users\Public\Documents\Intuit\QuickBooks\Company Files (default Intuit location)
2 - C:\Clients
2) In File Explorer's search function (upper-right corner), enter one of the following two search terms:
3) If any folders are found, first ensure that there are no files within them that should not be deleted (there should not be). Once you have confirmed that, highlight all folders (CTRL + A) and permanently delete them (SHIFT + DELETE).
4) In the two examples below, there were 12.4GB of QBBackupTemp folders, and 3.41GB of QuickBooksAutoDataRecovery folders, freeing up a total of 15.81GB on this server.