How to Fix Proof.Cab Errors on CDs

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If you are attempting to install Microsoft Office and some variation of the error "Cannot Find Proofing.en-us" occurs, you may be experiencing a common symptom of drive confusion. This occurs when the installer tries to locate a necessary component of the software but looks in the wrong place. You can fix this error and successfully install Office with a quick edit to the installer.


Step 1

Open the Windows search function by pressing the "Windows" key and the "F" key on your keyboard simultaneously.

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Step 2

Type "proof.msi" (without quotes) into the search field and press "Enter." You may need to use the "Advanced Search" option to search everywhere instead of the traditional indexed locations.


Step 3

Write down the location of the file once it has been located. The path should look something like this: C:\MSOCache\All Users{90120000-002C-0409-0000-0000000FF1CE}-C\Proof.en

Step 4

Run the Microsoft Office installation wizard again. When the error appears, go to the input field at the bottom of the error message and remove the "proofing.en-us\proof.en\proof.msi" from the file location using the "Backspace" key.


Step 5

Type the file location that you wrote down in Step 3 into the box at the bottom of the error message (this is the input field that you cleared in the preceding step). Press "Enter" to complete the installation.


If you are still experiencing this issue after performing the above troubleshooting steps, you can try disabling your system antivirus protection and running the installer again. Re-enable your antivirus protection after you finish installing Microsoft Office.


Never attempt to modify or move important system files while troubleshooting an error. You could cause further damage to your system.