CPU shows busy why this happens

I am using Soft share in virtual server which runs with Windows Server 2003 and have 8 GB RAM. The server performance is very slow. I have opened the task manager and it is showing whole CPU time is hogging by the task manager. But it is not getting fast when I close the task manager. Is it possible to view the actual CPU usage? If anybody knows why it is working slow, please let me know. I will thankful for all help and support.
