This really helped me out while working on virtual machines on my laptop.   I recommend all developers to have your virtual machines configured to use the Microsoft Loopback adaptor.

1. Click Start, and then click Control Panel.
2. If you are in Classic view, click Switch to Category View under Control Panel in the left pane.
3. Double-click Printers and Other Hardware, and then click Next.
4. Under See Also in the left pane, click Add Hardware,and then click Next.
5. Click Yes, I have already connected the hardware, and then click Next.
6. At the bottom of the list, click Add a new hardware device, and then click Next.
7. Click Install the hardware that I manually select from a list, and then click Next.
8. Click Network adapters, and then click Next.
9. In the Manufacturer box, click Microsoft.
10. In the Network Adapter box, click Microsoft Loopback Adapter, and then click Next.
11. Click Finish.

Now that you have installed the Microsoft Loopback Adapter, you can set your virtual machine to use the loopback adaptor.

KB839013 - How to install the Microsoft Loopback adapter in Windows XP