Yesterday I installed 7zip on Ubuntu 12.04 LTS and I was able to extract a .rar file by using the Archive Manager.
Right click -> Extract Here
Today I decided to reinstall Ubuntu 12.04 LTS. Then I installed 7zip from the Ubuntu Software Center and I tried to extract a .rar file the same way as last time and I see the following:
"Could not open this file type. There is no command installed for RAR archive files. Do you want to search for a command to open this file?"
I know that you can install unrar if you want to extract .rar files using the Archive Manager but I want to know why 7zip worked the last time and now after a fresh install it doesn't.