Problem: partition(s) in external hard disk (using hard disk docking station) was lost due (cannot be seen), sometimes Windows will prompt for formatting the hard disk. This problem is caused by:-

• “safely remove” was not used to remove the external hard disk;
• hard disk corruption

Solution: there are various recovery tools available

• TestDisk
• MiniTool Power Data Recovery
• Partition Find and Mount
• EaseUS Partition Master

TestDisk is the free and fast while the rest comes with limitations. In this tutorial, TestDisk will be used. The only disadvantage with TestDisk — using command line instead of GUI.

First of all, to recover the lost partition, the same hard disk docking station must be used. I have moved the external hard disk to another docking station and all the above recovery tools cannot detect the lost partition.

1. run “testdisk_win.exe“
2. select “Create”:-
   
3. select the hard disk having lost partition:-
   
4. if hard disk is formatted using Windows, then select “Intel”:-
   
5. select “Analyse”:-
   
6. select “Quick Search”:-
   
7. after “Quick Search”, it will detect lost partitions in green (in this example there are 2 partitions):-
   
8. select “Write” to recover the lost partitions:-
   
9. type “Y” to write partition:-
   
10. select “Ok” to reboot:-
    
11. select “Quit”:-
    
12. select “Quit”:-
    
13. After reboot the hard disk, the 2 lost partitions reappear:-
    
14. for more information refer to http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step#Quick_Search_for_partitions

Problem: when copying a large files from external hard disk 1 to external hard disk 2 (both are connected to Windows 7 PC via USB port), Windows PC will hang.

Applies to: Windows 7 Pro

Trouble Shoot: goto “Event Viewer” to determine if there is an error message “An error was detected on device \Device\Harddisk2\DR2 during a paging operation.”

Solution: enable “virtual memory” or “paging file” for the external hard disk.

Steps:

1. goto “Advanced system settings”
   
2. goto “Advanced  -> Performance -> Settings”
   
3. goto “Advanced -> Change”
   
4. uncheck “Automatically manage paging file size for all drives”, select the hard disk, check “System managed size”, then “Set”
   

Windows 7 PC will no longer hang or stall when copying large files.

Also refer to https://forums.techguy.org/threads/solved-an-error-was-detected-on-device-device-harddisk1-dr1-during-a-paging-operati.966724/