If your Windows Vista computer does not appear in the Clientless Backup page, or is displayed as a grayed icon, perform the following steps to enable file sharing.
To enable file sharing in Windows Vista
Open the Network and Sharing Center, by clicking Start > Control Panel, clicking Network and Internet, and then clicking Network and Sharing Center.
If network discovery is off, click the arrow button to expand the section, click Turn on network discovery, and then click Apply.
If file sharing is off, click the arrow button to expand the section, click Turn on file sharing, and then click Apply.
If you are still having trouble, make sure Windows Firewall is not blocking File and Printer Sharing. Do the following:
Open Windows Firewall by clicking the Start > Control Panel, clicking Security, and then clicking Windows Firewall.
Click Allow a program through Windows Firewall.
In the Program or port list, make sure the File and Printer Sharing check box is selected.