Error: “Can’t connect to your phone” when you try to connect Windows Phone 7 to a computer

Restart your computer and phone

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1. If this restart sequence doesn’t work for your phone, try one of the following options:
   
   • Press and hold the Power button and "slide down" when prompted. After it’s off, press the Power button to turn on your phone again.
   • If your phone has a replaceable battery, remove and then reinsert the battery located under your phone’s back panel. Then press the Power button to turn on your phone again.
2. As soon as your Windows Phone 7 has restarted, follow the manufacturer's recommended steps to restart your computer.
3. If your phone is still not detected:
   
   1. Restart the phone while it is attached to your computer.
   2. Press and hold the Power button and "slide down" when prompted. Your phone should automatically restart if plugged into a usable USB port.

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Verify your USB Connection

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• You are not using the correct USB data sync cable, such the one that came with the phone. Some phones are also supplied with optional "charging" cables that cannot be used to establish a data connection with a computer. Try another cable, if possible.
• There is dust or debris in the USB port on the phone. Try using a can of compressed air to clear the USB port on the phone to ensure a good connection.
• The computer's USB port is bad. Try connecting to another port directly on the computer (don't use a USB hub).

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Trust the Zune certificate

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1. Close the Zune software and disconnect your phone from your computer.
2. Open Certificate Manager. To do this, click Start, type certmgr.msc in the Start search bar, and then press your Enter key.
   
   Windows 8 users: On the Start screen, type Certificate, tap or click Settings in the right column, and then tap or click Manage computer certificates.
3. In the pop-up window, tap or click the Personal folder in the left column, and then double tap or double click the Certificates folder in the right column.
4. Click the heading that says Issued By to sort the column, and then look for one or more certificates that read "zune-tuner://windowsphone/...".
5. Right-click the certificate file and click Copy. If there is more than one file, hold the Ctrl key, click each file, then right-click a file and click Copy.
6. Tap or click the Trusted Root Certification Authorities folder in the left column, right-click the Certificates folder, and then click Paste.
7. Click Yes to install this certificate.
   

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Create a new certificate and then restore files

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1. Create a new certificate
   1. Close the Zune software and disconnect your phone from your computer.
   2. Open Certificate Manager, if it is not already open. To do this, click Start, type certmgr.msc in the Start search bar, and then press your Enter key.
      
      Windows 8 users: On the Start screen, type Certificates, tap or click Settings in the right column, and then tap or click Manage computer certificates.
   3. In the window, tap or click the Personal folder in the left column, and then double tap or double click the Certificates folder in the right column.
   4. Click the heading that says Issued By to sort the column, and then look for one or more certificates that read "zune-tuner://windowsphone/...".
   5. Right-click each certificate file, click Delete, and then click Yes.
   6. Tap or click File in the menu, then Exit.
   7. Click Start and in the search box enter %userprofile%\Application Data\Microsoft\Crypto\RSA, and then press Enter.
      
      Windows 8 users: Right-click in the lower left-hand corner of the screen and tap or click Run, or type Windows Key + R, and then type the string above.
      
      Note For some enterprise customers, the string will be %userprofile%\AppData\Roaming\Microsoft\Crypto instead.
   8. Find the folder that begins with "S-1-5-21-".
   9. Right-click the folder and then click Rename. Rename the folder so that it ends in .bak. This means you will likely be adding ".bak" to the end of the number.
      
      Note If there is more than one folder that begins with "S-1-5-21-", try this procedure with one folder at a time. If it does not work, rename the folder to the original name and try the next folder.
   10. As soon as you're done, open your Zune software and connect your phone to your computer. This creates a new certificate and folder.
   If you go back to your .bak certificate folder, and you may see some remaining files there. If this is the case, you should copy and paste these files in order to restore them to their previous state. To do this, see the following step.
   
2. Restore any remaining files
   
   To restore any files remaining in the .bak folder, you have to copy those files from that folder and paste them into the newly created one.
   
   
   1. Click Start and in the search box type %userprofile%\Application Data\Microsoft\Crypto\RSA, and then press Enter.
      
      Windows 8 users: Right-click in the lower left-hand corner of the screen and tap or click Run, or type Windows Key + R, and thentype the string above.
      
      Note For some enterprise customers, the string will be %userprofile%\AppData\Roaming\Microsoft\Crypto instead.
   2. Tap or click the RSA folder.
   3. Find and open the folder that you renamed to end in .bak.
   4. Press Ctrl+A on your keyboard to select all the files, and then press Ctrl+C to copy them.
   5. Press the back button on your screen to return to the RSA folder.
   6. Locate and open the new folder that begins in "S-1-5-21-" and does not end in .bak.
   7. Press Ctrl+V to paste the files. When you see the warning "There is already a file with the same name in this location," click Don't Copy.
   8. Close the folder.
   
   
   Disconnect your Windows Phone from your computer and reattach it to see if it is recognized. If not, try the next section.

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Perform a custom installation of the Zune software

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Step 1: Remove and reinstall the Zune software

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• This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
• If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD so that you can run it on the computer that has the problem.

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Step 2: Run the Zune software as an administrator

1. Click Start, and then type Zune.
   
   Windows 8 users:On the Start screen, type Zune.
2. Under Programs, right-click Zune, click Run as administrator, and then click Yes.
   
   Windows 8 users: Under Apps, right-click Zune, and then at the bottom of the screen, click Run as administrator.

Step 3: Reset your Zune collection and device settings

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• This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
• If you are not on the computer that has the problem, you can save the automatic fix to a flash drive or to a CD so that you can run it on the computer that has the problem.

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Known compatibility issues

1. Uninstall the cryptographic program.
2. Connect your Windows Phone to your computer. This creates the certificate needed.
3. Reinstall the cryptographic program.

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