Remote Desktop Update - To access Windows 7 computers with Remote Desktop running on Windows XP SP3, Windows Vista SP1, and Windows Vista SP2 computers, you'll need to download the Remote Desktop Connection 7.0 client update and install it.
Networking XP with Vista - To share files between computers running Windows XP and Vista, download the LLTD Responder and install it on your Windows XP (Home & Pro) Service Pack 2 computers. The LLTD Responder allows a Windows XP computer to respond to Vista computers on your network that are trying to create a network map.