Describes how to troubleshoot problems that occur when you install, uninstall, or upgrade a program on a Windows-based computer by using Windows Installer.

If some Windows functions aren't working or Windows crashes, use the System File Checker to scan Windows and restore your files. Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track.

You can use installation media (a USB flash drive or DVD) to install a new copy of Windows, perform a clean installation, or reinstall Windows. To create installation media, go to the software download website, where you'll find step-by-step instructions.

Uninstall or remove apps and programs in Windows. There are different ways to remove apps and programs, so if you can't find the one you're looking for, you can try another location. Note that some apps and programs are built into Windows and can't be uninstalled.

You can repair some apps and programs if they're not running correctly. Note that you won't see repair, change, or modify options for all apps and programs. Repair options from the Settings page. Select Start > Settings > Apps > Apps & features. Apps & features in Settings.

Learn how to remove malware from your PC. Use Microsoft Defender Antivirus in Windows 10 or Windows 11 to scan your PC for malware, viruses, or other threats.

Select File > Get Add-ins. Alternatively, you can also view your add-ins directly from the Home tab by selecting Add-ins . You can directly install add-ins from this page or select More Add-ins to explore. In the Office Add-ins dialog, select My Add-ins tab.

Your PC isn't working well and you recently installed an app. Restore from a system restore point. You suspect your device has been infected. Use installation media to reinstall Windows 11. Select one of the recovery options below and follow the steps to try to get things working again.

Check for Windows updates. Learn how to update drivers in Windows using Device Manager to update or reinstall a driver.

From the Overview page, select Office apps and on that page, find the Microsoft 365 product you want to install and select Install. To install Microsoft 365 in a different language, or to install the 64-bit version, use the dropdown to find more options.