ubuntu black screen after login

After getting that black screen I pressed ctrl + alt + f1 key, then after loging in with primary username. yellow 138 slot login I started typing these command: sudo apt-get install ppa-purge ppa-purge ppa:unity-team/staging sudo apt-get update sudo apt-get intall --reinstall ubuntu-desktop sudo apt-get install unity METHOD 2 . betwin4d login link alternatif