I am trying to backup my system and some data files onto an external USB drive but get an error: The backup was not successful. The error is: There is not enough free space on the backup storage location to back up the data. (0x80780048). There is enough space on my drives. - System - Provider [ Name] Windows Backup - EventID 4104 [ Qualifiers] 0 Level 2 Task 0 Keywords 0x80000000000000 - TimeCreated [ SystemTime] 2010-01-01T04:39:30.000000000Z EventRecordID 14721 Channel Application Computer i7 Security - EventData There is not enough free space on the backup storage location to back up the data. (0x80780048) 48007880CB0500003F0900005B090000420ED1665C2BEE174B64529CB14610EA71000000 Binary data: In Words 0000: 80780048 000005CB 0000093F 0000095B 0008: 66D10E42 17EE2B5C 9C52644B EA1046B1 0010: 00000071 In Bytes 0000: 48 00 78 80 CB 05 00 00 H.x€Ë...0008: 3F 09 00 00 5B 09 00 00 ?...[...0010: 42 0E D1 66 5C 2B EE 17 B.Ñf\+î.0018: 4B 64 52 9C B1 46 10 EA KdRœ±F.ê0020: 71 00 00 00 q...

and that amount of space available on the external drive is as reported by disk management? MCSE, MCSA, MCDST [If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.]

455G free and I want to backup 113G. See screen shoot of the disk manager here: http://img34.imageshack.us/img34/3874/diskmanager.png

Does the issue occur when you only backup files or when the backup progress is doing image backup? You may unselect system image backup and run backup again and check the result. Please refer the screenshots in the following thread. Win7 System Image - All Logical Drives Are Selected Please uncheck the image backup for each drives, and also uncheck “Include a system image of drives…”. If the issue does not occur this time, it should occur during the system image backup process. If you were trying to make images for every drives during backup, the disk space of the backup storage may be not enough. How does it work if you run “Create a system image” in “Control Panel\All Control Panel Items\Backup and Restore”?Arthur Xie - MSFT

Hello lasse,Just came across this thread. For future posts regarding backup please post below:http://social.technet.microsoft.com/Forums/en-US/windowsbackup/threadsFor this case, can you please collect the logs from under C:\windows\logs\windowsbackup\*.etl , zip them and send them across to lokkum"at"microsoft"dot"com(replace words with characters). Appreciate your participation,Lokesh [MSFT]