Busuabo,
I am not sure of the normal procedure to enable the task manager but I was able to do it on a system at work by using a registry hack. Go to google and search for a registry hack to enable the taskbar. You will have to create a registry key to do this. I would recommend backing up your registry before you do this. Also, if you don't feel comfortable editing the registry then I would recommend leaving it for someone else to do. Hope this helps.
Nick