Make sure you've generated a unique Device Setup Password via the Sony website on your phone or PC, as your regular PSN password will no longer work on the Vita.
PS Vita System Software Update 3.74: Everything You Need to Know ps vita system software update 374 download upd
If your PS Vita is running , you should exercise caution. Make sure you've generated a unique Device Setup
If your Wi-Fi is spotty, you can download the update via a computer: Connect your Vita to your PC via USB. Open the on your computer. ps vita system software update 374 download upd