How to Fix 1603 Fatal Error Windows 10

The Windows Installer is a program which installs and removes the software from the computer system. But sometimes, the program doesn’t work correctly as it conflicts in the operating system. As a result, the Windows Installer doesn’t install any software and display the error called 1603 Fatal Error during installation. But there are some methods mentioned in the article to help you fix the 1603 error in Windows 10.

Ways to Troubleshoot 1603 Fatal Error Windows 10

Close Background Programs

Programs and software running in the background can affect the Windows Installer while it is installing the program on the computer. Close every program running on the system and proceed to follow the steps.

  1. Press Ctrl + Shift + Esc key combination.
  2. Now the Task Manager will open in the system.
  3. Click the Processes tab from the upper toolbar.
  4. Now, close all software and programs running in the system.
  5. Click the program and proceed to click the End Process tab from the bottom.

Check If Software is Already Installed

If the system is showing the 1603 error in Windows 10, then you must ensure if the program is already installed or not. If not, then you must have installed the earlier version of the software in your system. To uninstall the previous version:

  1. Press window key + R and type appwiz.cpl in the Run program.
  2. It will open the Programs and Features folder.
  3. You must be seeing the list of all installed software and programs.
  4. Select the program and click Uninstall from the upper bar.
  5. If prompted then click the Yes tab to confirm the removal.

Ensure that Hard Drive has Space

First, check the system requirement of the program you are downloading and then check the space left in your Hard Drive.

  1. Click to open the File Explorer.
  2. From the left pane of the window, click This PC button.
  3. Now, the list of folders and drives will appear on the screen.
  4. Right click on the C: Drive.
  5. Select the Properties from the menu.
  6. Now click the General tab from the upper toolbar.
  7. The general tab will reveal the actual space occupied and space left in the C: Hard Drive.

Remove the Temporary Files

The 1603 error in Windows 10 can appear due to the temporary software files. Hence removing the temporary files is a significant task to perform for maintaining the performance of the computer.

  1. Open Cortana app in your Computer.
  2. Now, enter the Disk clean up in the search box.
  3. Click to open Disk Cleanup from the search results.
  4. When the Disk Cleanup pops up, then select C: drive from the drop-down menu.
  5. Click the Ok button to proceed in the process of clean up.
  6. Select the Temporary Files and Temporary Internet Files from the given options.
  7. You can also select the other options but select carefully. You cannot recover the removed files.
  8. Now, click Ok button and proceed to select Delete Files option.

The 1603 error is now resolved from your Windows 10 computer system. The methods are capable enough to solve the error so that the system can resume installing the programs. Hopefully, you have followed the methods thoroughly to remove the error and fixed the issue.

Carl Smith is a self-professed security expert; he has been making the people aware of the security threats. His passion is to write about Cyber security, cryptography, malware, social engineering, internet and new media. He writes for Norton security products at

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