Change from a 32-bit version to a 64-bit version or vice versa. Activate Windows. Fix Bluetooth problems in Windows. Learn how to install, reinstall, or activate Microsoft 365 or Office 2019 on a PC or Mac.

Change screen brightness in Windows. Select the Network icon on the right side of the taskbar, and then move the Brightness slider to adjust the brightness. (If the slider isn't there, see the Notes section below.)

How to open PC Health Check. In Windows, use Search on the taskbar to search for “PC Health Check,” then select it from the list of results. If a PC Health Check update is available, you can quickly install it for the latest version.

Microsoft support is here to help you with Microsoft products. Find how-to articles, videos, and training for Microsoft Copilot, Microsoft 365, Windows, Surface, and more.

Possible causes. Make sure your PC, the external display, and the cable all support DisplayPort or MHL alternate modes. Make sure the device or dongle is connected directly to your PC. Make sure the device or dongle is connected to the USB-C port on your PC that supports the correct Alternate Mode.

A product key is a 25-character code that's used to activate Windows and helps verify that Windows hasn't been used on more PCs than the Microsoft Software License Terms allow.

TPM 2.0 is used in Windows 11 for a number of features, including Windows Hello for identity protection and BitLocker for data protection. In some cases, PCs that are capable of running TPM 2.0 are not set up to do so. If you are considering upgrading to Windows 11, check to ensure TPM 2.0 is enabled on your device.

Go to Settings > Apps > Apps & features to change whether you're shown app recommendations when trying to install apps from outside the Store.

If Device encryption is turned off, turn it On. Turn on standard BitLocker encryption. Sign in to your Windows device with an administrator account (you may have to sign out and back in to switch accounts). For more info, see Create a local or administrator account in Windows.

Try guided support. If you're having problems setting up your email in Outlook, we want to help. Choose an option below for more information. Tip: If you're a small business owner looking for more information on how to get Microsoft 365 set up, visit Small business help & learning.