[SOLVED] How to clean up temporary and obsolete files or packages?

view story

http://ubuntuforums.org – I am a recent migrant to Ubuntu Linux 12.04 LTS. Recently, I have had upgraded my softwares (system update) after which, my system's performance has slowed down a bit from what I see while opening applications. In the past, I have had used Janitor to clean up my system but for some reason, I am not able to use it after upgrading my system (it repeatedly generated errors) and hence I had removed Janitor and installed BleachBit instead. Now, BleachBit reports me that following message upon scan: Disk space to be recovered: 628.7MB Files to be deleted: 898 Special operations: 31 How (Hardware)