To assist you better, please provide us more information.
a)Where have save the even log file?
b)Are you getting any error message when you are trying to back up files?
I would suggest you to check in event viewer what is causing the issue. To do so, please follow the steps below:
1. Open Event Viewer by clicking the Start button, clicking Control Panel, clicking System and Security, clicking
Administrative Tools, and then double-clicking Event Viewer. If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.
2. Click an event log in the left pane.
3. Double-click an event to view the details of the event. Refer this link for information on event viewer:
If you have any security software and firewalls, I would suggest you to temporarily disable all the firewalls and security
software settings and then try to backup and check whether it helps.
Also check whether any partition is FAT, if yes then covert the partition from FAT to NTFS. To do so, please follow the
1.Close any open programs running on the partition or logical drive to be converted.
Start button, click
click Accessories, right-click Command Prompt, and then click Run as administrator.
If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
3.In the Command Prompt window, type
convert drive_letter: /fs:ntfs, where
drive_letter is the letter of the drive you want to convert, and then press ENTER. For example,
convert E: /fs:ntfs would convert drive E to the NTFS format.
4.Type the name of the volume you want to convert, and then press ENTER. To view the available volumes, click the
Start button, and then click Computer. The volumes are listed under Hard Disk Drives.
For more information, please refer the link mentioned below;