For most Windows 10 users, no download is needed . Use the native Windows 10 Telugu phonetic keyboard. If you need advanced features, download Google Input Tools from its official site only.
Press Windows key + Spacebar or click the language icon on the taskbar. Download Telugu Typing Software For Windows 10
This official tool from Microsoft supports multiple keyboard layouts, including Transliteration and InScript. For most Windows 10 users, no download is needed