Yes. This model ships with Windows 10 S-Mode Operating System. Windows 10 S-Mode provides added security by only allowing APPs available ( and therefore certified by Microsoft) at the Microsoft Store. If you don't need the added security or you need to install APPs not available at the Microsoft Store, you can switch to standard Windows 10 Home 64-bit Operating System, at no additional cost. Be sure the software you plan on installing is compatible with Windows 10 (you will need to switch from S-Mode to install programs not available through the Microsoft Store), and this device configuration. There is a 64GB eMMC solid state hard drive with approximately 40GB of storage space available to the user.

The battery is only replaceable by a certified technician, it is not user replaceable.

This is a Chromebook. It uses Google Docs through the Google Server. Google Docs is completely compatible with Microsoft Office Programs. This is a free service for Chromebook users. If you must have the Microsoft Office Specific programs, you can purchase Microsoft Office 365 for this Chromebook at the Google Play Store.

No, this model does not have a backlit keyboard. The Lenovo IdeaPad S145-15 model number 81N3005LUS is not user upgradable. A certified technician must do all of the work, so as to not void the warranty. This model ships with 4GB of RAM in the one RAM memory slot. The maximum RAM this model can support is 8GB, so your certified technician can replace the existing 4GB RAM memory stick with an 8GB RAM memory stick.