For the Mac® equivalent, visit our Repair Disk Permissions and Repair Disk guide.

Run ScanDisk and Disk Defragmenter regularly to keep system file management at peak performance. Make sure you have closed all background applications as they may cause issues.

Please make a selection.

Windows® 10

ScanDisk

  1. Click Start.
  2. Type This PC and press Enter.
  3. Right-click the hard drive you want to scan and select Properties.
  4. Select the Tools tab.
  5. Click Check.

Defrag

Do not perform disk defragmentation on Solid State Drives. If you aren't sure what type of disk drive you have, consult your PC manufacturer.

  1. Click Start.
  2. Type This PC and press Enter.
  3. Right-click the hard drive you want to scan and select Properties.
  4. Select the Tools tab.
  5. Click Optimize.
  6. Select the drive or volume and click Optimize.

System File Checker

Missing system files may cause issues with Blizzard games. Run the System File Checker to scan for damaged or missing files in Windows.

Note: This command may require access to the Windows installation source files.

  1. Click Start.
  2. Type cmd.
  3. Right-click Command Prompt and select Run as Administrator.
  4. Type sfc /scannow and press Enter.
  5. Follow the prompts to check the integrity of your files.

Windows® 7 and Windows® 8

ScanDisk

  1. Click the Start button (Windows Key + Q in Windows 8).
  2. Click Computer.
  3. Right-click the hard drive that you want to check.
  4. Click Properties.
  5. Select the Tools tab.
  6. Under Error-checking, click Check Now.
  7. Select Scan for and attempt recovery of bad sectors and Automatically fix file system errors.
  8. Select Yes to schedule after restart.
  9. Restart your computer to run the scan.

Defrag

  1. Click Start (Windows Key + Q in Windows 8).
  2. Select Computer.
  3. Right-click the hard drive that you want to check.
  4. Select Properties.
  5. Click the Tools tab.
  6. Under Defragmentation, click Defragment Now.
  7. Select the volume to defragment.
  8. Click Defragment.

System File Checker

Missing system files may cause issues with Blizzard games. Run the System File Checker to scan for damaged or missing files in Windows.

Note: This command may require access to the Windows installation source files.

You will first need to open an elevated command prompt window.

  1. Click Start (Windows Key + Q in Windows 8).
  2. Select All Programs.
  3. Under Accessories, right-click Command Prompt.
  4. Click Run as Administrator.
  5. In the Command box, type sfc /scannow.
  6. Follow the prompts to check the integrity of your files.