BackTrack 5 R1 on virtualbox won't work

Hi,

I'm just curious about Backtrack, so I thought I would install it to virtual box to play with before I make it a real install.
I went through all the install just fine, but when I try rebooting it into the operating system it tells me to put in the username and password. which is the backtrack default. After I input that it takes me to the desktop which still has the install icon on the desktop and tries to make me go through the install process again.
Have I done something wrong?

Thank you