After purchasing Avast Battery Saver, you need to activate the product using either a valid activation code, or via your Avast Account that is registered with the same email address you used to make the purchase.
Before following the activation steps in this article, ensure the latest version of Avast Battery Saver is installed on your PC. For installation instructions, refer to the following article:
Activate Avast Battery Saver
All your Avast subscriptions automatically appear in the Avast Account registered with the same email address you used to make the purchase.
If you do not have an Avast Account yet, refer to the following article for instructions:
To activate Avast Battery Saver via your Avast Account:
- Double-click the Avast Battery Saver icon on your desktop to open the application...
...or right-click the
Avast Battery Saver icon in the system tray and select Avast Battery Saver. 
- Go to
☰
Menu ▸ My licenses. 
- On the My licenses screen, click Log in to your Avast Account.

- Enter your Avast Account credentials and click Log in. Alternatively, select Facebook or Google to log into your Avast Account using your existing Facebook or Google credentials.

- Check your subscription details for the connected Avast Account. If you have any subscriptions for interchangeable products, you can click on a listed item and select an alternative subscription from the drop-down menu. Then click Continue to return to the My licenses screen.

Your subscription for Avast Battery Saver is now activated. The expiration date of your subscription appears under Subscriptions on this PC.
For detailed instructions to begin using Avast Battery Saver, refer to the article below:
Troubleshoot activation issues
To troubleshoot activation issues, reinstall Avast Battery Saver on your PC and activate it again. For reinstallation instructions, refer to the following articles:
In some cases, subscription synchronization may take up to 24 hours after purchase. If your subscription is still not active after this time, refer to the following article:
- Avast Battery Saver 19.x for Windows
- Microsoft Windows 10 Home / Pro / Enterprise / Education - 32 / 64-bit
- Microsoft Windows 8.1 / Pro / Enterprise - 32 / 64-bit
- Microsoft Windows 8 / Pro / Enterprise - 32 / 64-bit
- Microsoft Windows 7 Home Basic / Home Premium / Professional / Enterprise / Ultimate - Service Pack 1, 32 / 64-bit