If no custom ROM exists for your device, you upgrade from 2.3.6 to 4.4.2. The kernel and drivers are incompatible. In that case, consider:
Custom ROMs often do not include Google apps (Play Store, Gmail, etc.) due to licensing. You will need to download a "GApps" package specifically for Android 4.4.2. upgrade android 2.3 6 to 4.4 2
: Moving to 4.4.2 replaced the dark, neon-green accents of Gingerbread with a clean, white-themed UI. The notification bar became translucent, and icons looked sharper and more modern. If no custom ROM exists for your device, you upgrade from 2