Windows 7 / Getting Started

Previous Versions and Shadow Copies

Windows 7 can also restore earlier versions of files so that users can quickly recover a file that has been accidentally modified, corrupted, or deleted. Depending on the type of file or folder, users can open, save to a different location, or restore a previous version. The sections that follow describe the Volume Shadow Copy technology and the Previous Versions user interface.

How Volume Shadow Copy Works

To provide backups for files that are in use, Windows 7 uses the Volume Shadow Copy service, which was first introduced with Windows XP. Volume Shadow Copy mitigates file access between applications and the backup process. In other words, if a backup tool needs to access a file currently in use, Volume Shadow Copy creates a shadow copy of that file and then provides the backup process access to the shadow copy. Figure below illustrates the relationship between Volume Shadow Copy features.

Volume Shadow Copy allows you to back up open files

Volume Shadow Copy works with any application. Some applications, however, can communicate directly with the Volume Shadow Copy service to ensure that backed-up files are consistent. If an application keeps several files in use at the same time, they might become inconsistent if two files must be synchronized and one of those files is updated after another is backed up in an earlier state.

Note Application developers can build Volume Shadow Copy integration into their applications using the Volume Shadow Copy Service software development kit (SDK). For more information, go to

To provide backup access to a file that is open and being updated, Volume Shadow Copy needs to be able to make two versions of the file accessible: one that is currently in use by the application and a second that is a snapshot of the file when backup first requested access to a volume shadow copy. Volume Shadow Copy handles this transparently by storing copies of changed files in Volume Shadow Copy storage. Volume Shadow Copy stores a copy of the original state of any modified portion of a file, which allows the original file to be updated without interrupting the backup process. In other words, if a user modifies a file after the backup starts, the file will be in the state it was in when the backup began.

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In this tutorial:

  1. Managing Disks and File Systems
  2. Overview of Partitioning Disks
  3. How to Choose Between MBR or GPT
  4. Converting from MBR to GPT Disks
  5. GPT Partitions
  6. Choosing Basic or Dynamic Disks
  7. Working with Volumes
  8. How to Create a Simple Volume
  9. How to Create a Spanned Volume
  10. How to Create a Striped Volume
  11. How to Resize a Volume
  12. How to Delete a Volume
  13. How to Create and Use a Virtual Hard Disk
  14. File System Fragmentation
  15. Backup And Restore
  16. How File Backups Work
  17. File and Folder Backup Structure
  18. How System Image Backups Work
  19. How to Start a System Image Backup from the Command Line
  20. How to Restore a System Image Backup
  21. System Image Backup Structure
  22. Best Practices for Computer Backups
  23. How to Manage Backup Using Group Policy Settings
  24. Previous Versions and Shadow Copies
  25. How to Manage Shadow Copies
  26. How to Restore a File with Previous Versions
  27. How to Configure Previous Versions with Group Policy Settings
  28. Windows ReadyBoost
  29. BitLocker Drive Encryption
  30. How BitLocker Encrypts Data
  31. How BitLocker Protects Data
  32. TPM with External Key (Require Startup USB Key At Every Startup)
  33. TPM with PIN (Require PIN At Every Startup)
  34. TPM with PIN and External Key
  35. BitLocker To Go
  36. BitLocker Phases
  37. Requirements for Protecting the System Volume with BitLocker
  38. How to Enable the Use of BitLocker on the System Volume on Computers Without TPM
  39. How to Enable BitLocker Encryption on System Volumes
  40. How to Enable BitLocker Encryption on Data Volumes
  41. How to Manage BitLocker Keys on a Local Computer
  42. How to Manage BitLocker from the Command Line
  43. How to Recover Data Protected by BitLocker
  44. How to Disable or Remove BitLocker Drive Encryption
  45. How to Decommission a BitLocker Drive Permanently
  46. How to Prepare AD DS for BitLocker
  47. How to Configure a Data Recovery Agent
  48. How to Manage BitLocker with Group Policy
  49. The Costs of BitLocker
  50. Windows 7 Encrypting File System
  51. How to Export Personal Certificates
  52. How to Import Personal Certificates
  53. How to Grant Users Access to an Encrypted File
  54. Symbolic Links
  55. How to Create Symbolic Links
  56. How to Create Relative or Absolute Symbolic Links
  57. How to Create Symbolic Links to Shared Folders
  58. How to Use Hard Links
  59. Disk Quotas
  60. How to Configure Disk Quotas on a Single Computer
  61. How to Configure Disk Quotas from a Command Prompt
  62. How to Configure Disk Quotas by Using Group Policy Settings
  63. Disk Tools
  64. EFSDump
  65. SDelete
  66. Streams
  67. Sync
  68. MoveFile and PendMoves