I first started using Ubuntu at v13.04 last monday straight onto my new computer, it has only seen Ubuntu. When i bought the desktop i also purchased a D-Link DWA-123 Model USB wifi adapter. It was discovered (although very slow) when using my live-cd to install Ubuntu, however after installation it stopped all together. I then moved my desktop to the router and used Ethernet to run updates and after these updates the wifi adapter was discovered again, however due to playing around with endless "fix"s all over the ask Ubuntu forums i believe i may have mixed up some of the setting around for my drivers. When i start up my desktop my D-link adapter is undiscovered, after openning the terminal and using "sudo modprobe rt2800usb" it is discovered but is very slow and i have attempted to download games in steam and watching the download rate flat line for a few seconds then spike up to maybe 100-200kb/s then flat again. Using my laptop at the same location running win7 i can download at a rate of 400kb/s+ actual download rate through steam, and the internet connection on it is fine.
After having no luck with finding a fix i went out today and purchased a TP-Link TL-WN823N usb wifi adapter. According to the ubuntu or linux compatability page (don't remember which one i was referencing) all models around this one have been reviewed and have been supported for plug and play working at high speeds. I plug it into my desktop and it is undiscovered, i believe from all the forum scrolling i have done that it is a driver issue. As i said this is my first time running Ubuntu and i am very much over this wifi problem (also my sound isn't working, and i have gone into alsamixer and turned auto-mute off, but this is a secondary problem, need wifi working asap). I am not overly familiar with the terminal commands for Ubuntu, so whoever reads this post and has help to offer may you please thoroughly explain what terminal commands etc. i should do to show drivers or make changes as you instruct. Will be checking this constantly so will has fast replies and be so very grateful to anybody who can help me fix this. That is: 1. Get TP-LINK TL-WN823N USB detected and at high speed. 2. If no chance of getting TP-LINK to work, fix D-LINK (certain TP-LINK will be easier) 3. Fix no-sound issue