There are some bugs in the VirtualBox "Shared Folders" feature. It can be convenient to work-around this in a secure way by using the Microsoft Loopback Adapter. Here's how I set it up for a Windows XP guest running on an XP host.
- Set up the Microsoft Loopback Adapter on the host:
- Open Control Panel, and start "Add Hardware"
- Select "Yes, I have already connected the hardware"
- Select "Add a new hardware device"
- Select "Install the hardware that I manually select from a list"
- Select "Network Adapters"
- Select "Microsoft" and "Microsoft Loopback Adapter"
- Assign the static address 192.168.2.1 to it.
- Next?