WindowsXP abd Vista sharing

>I have read the messages of sharing Vista (Home Premium) and WindowsXP SP2.
>I am trying to set up a network between my desktop computer (OS WindowsXP
>SP2) and my HP Pavilion dv6690ej laptop (OS Vista Home Premium Hebrew
>edition). Both computers use the Windows Firewall. The router is the Siemens
>SL2-141 Modem router. The desktop computer is connected to the router through
>a Lan connection while the laptop is connected by a wireless connection.
>The problem:
>Both computers are configured to have the same workgroup: MSHOME.
>While the WindowsXP computer recognizes the folders in the laptop (Vista),
>and can open the folders and files, the laptop recognizes the existence of
>the logical drives and folders in the desktop, but does not allow to open
>them, giving a message (freely translated from Hebrew):
>"There is no possibility to access the drives or folders in the XP desktop
>because maybe you do not have permission do so. Contact to the Network
>manager(?) to see if you have an access permission.
>There is not enough storage (?) to operate this process"
>Please comment and help