I have a server setup with Ubuntu 11.04 running the latest version of Virtualbox 4.1.4. The server has 4gigs of ram and a Core i5 processor with 4 cores. I have a guest system setup with Windows Server 2003. I have setup the guest system with 2gb ram and access to all 4 cores. When I load the os up, the task manager only reports one processor core. But the virtual machine status shows that it is giving access to all 4 cores. Is there some sort of limitation in Windows server 2003 that would prevent me from seeing all 4 cores?