QuickBooks is accounting software used to perform financial tasks easily. A backup copy is created whenever new data is entered within QuickBooks. Certain times QuickBooks Unable to Backup Company File. There could be various reasons for it. It can be due to the unavailability of the storage device, which backs up the latest files. Some kind of damage must have occurred within the company file. The path leading to the backup folder must be incorrect. The company file name may have more than 65 characters. The hard disk where the backup files are stored must be corrupted.