Firstly, both computers should be in the same Workgroup but have individual names. In XP, set any folders and printer(s) that you want to have available over the network as "shared" by right clicking them and selecting the Sharing & Security option. Any firewall software needs to be configured to allow access to the networked computers, which may involve adding their IP addresses in a "trusted" section. That is basically it in XP. Its icon should appear in "My Network Places" in the XP PC and in "Network" in the Vista laptop.
For File & Printer Sharing in Vista, go into the "Network and Sharing Center" and ensure you have switched "On":
Public Folder Sharing
Printer Sharing (if sharing a printer hosted in the Vista computer)
For more comprehensive instructions on Vista networking:
VISTA NETWORKING ?
To enable access to a Vista PC from another computer both should be in the same “Workgroup” which, ideally, should be a name of your own and not the Windows default name.
To change the “Workgroup” name in Vista, right-click Computer and select “Properties”. In the System window, the Workgroup name is listed in the Computer Name, Domain, and Workgroup settings section - click the “Change Settings” link if you need to rename your workgroup. ?
Next, setup the Network Location Type: Domain, Public or Private (select Private if you are setting up a home network or small office network located behind an Internet gateway such as a router). Vista will then automatically configure security and other settings based on the type of network selected. To view the Network Location Type, click Start, right click Network, and select Properties. This opens the “Network & Sharing Center” where the type will be shown in brackets after the Network Name.
If the Network Location Type is set to “Private”, Network Discovery is automatically enabled in the Sharing and Discovery section of the Network and Sharing Center window. You should manually enable File Sharing, Public Folder Sharing and, if appropriate, Printer Sharing and Password Protected Sharing.
To enable File Sharing: ?
In the Sharing and Discovery section of the Network and Sharing Center window, click the down arrow next to File sharing. Within the File sharing settings, click Turn on file sharing, and then click Apply. ?
To enable Public Folder Sharing: ?
In the Sharing and Discovery section of the Network and Sharing Center window, click the down arrow next to Public folder sharing. Within the Public folder sharing settings, click one of the following: ?
a) If you want to share the Public Folder so that other computers on the network can access it to open files, but not create or change files, select “Turn on sharing so anyone with network access can open files”.
b) If you want to allow users to create or change files, select “Turn on sharing so anyone with network access can open, change, and create files”. Click Apply.
To enable printer sharing: ?
In the Sharing and Discovery section of the Network and Sharing Center window, click the down arrow next to Printer sharing. Within the Printer sharing settings, select “Turn on printer sharing” and click Apply. ?
Password Protected Sharing:
To enable password protected sharing:
In the Sharing and Discovery section of the Network and Sharing Center window, click the down arrow next to Password Protected Sharing. Within the Password protected sharing settings, click “Turn on password protected sharing” and click Apply. ?
File Sharing Settings:
To share a folder in Vista, ensure that File Sharing is enabled as above then navigate to the Folder that you want to have available as “shared” over the network. Right click it and select “Share”. The File Sharing properties sheet opens. If you have Password Protected Sharing enabled, use the File Sharing properties sheet to select which users have access to the shared folder and their permission level. To allow all users, select Everyone in the list of users. To allow a user to change files or folders or create new files or folders, select Co-owner as the permission level. If you do not have Password Protected Sharing enabled, use the File Sharing window to select the Guest or Everyone account, which is the equivalent to XP’s “Simple File Sharing” in Windows XP. Click “Share” and then “Done”.