I installed ubuntu 12.04 on Virtual box. At the beginning it went well, after a few system updates and software installation now it's only crawling. Where do I start to diagnose the problem? I'm new to linux. In the last 3 months I've tried ubuntu and mint. Every time I had a problem (stuck at boot, and all other kinds of weird problems) with linux, all I can do was reinstallation. The longest time the linux could run normally was 7 days, until a new reinstallation. It is totally frustrating.