hp envy 7855 driver

Agree with rkaufmann97, you need to spell out the entire device name.

The networked, HP ENVY Photo 7855 All-in-One printer is supported by Apple's AirPrint technology. Follow the instructions from Apple's article, If you can't print from your Mac or iOS device, and choose AirPrint from the re-add device panel, instead of the HP drivers.

Run software update and if one is available then it will download. However I think you may benefit by looking over Writing an effective Apple Support Communities ... Apple Support Communities as your post does not give us adequate information to really assist you.