I don't have a Vista machine in front of me right now and XP does not support the 'wlan' component of netsh. Try the following:
Export using this command:
netsh wlan export profile folder=C:\
(replace C:\ if you want to direct to a different folder)
Import using this command:
"netsh wlan add profile filename=c:\exported_filename.xml user=all
(replace "C:\exported_filename.xml" with appropriate location and filename)