If your windows 7 can’t access shared folder or printer on windows xp(similar error log on screenshot below) ,please follow below guide to do troubleshooting.
1.Make sure you can see the windows xp ‘s computer name via network,if not,please refer below post to let them can see each other.
2.Go to Start / Control Panel / Administrative Tools / Local Security Policy / Local Policies / Security Options ,
3.Change Network security: LAN Manager authentication level to Send LM & NTLM – use NTLMv2 session security if negotiated
4. If you are using Windows 7 home edition,because there is no Local Security Policy Editor ,so you need to tweak your registry.
a) Go to Start ,type in regedit ,then press Enter to open Registry Editor
b)Brower to :
c) in the right pane,right click to create a DWORD Value ,name it to LmCompatibilityLevel ,and set the value to “1″
5.Exit registry editor and Reboot to confirm you can access windows xp share from windows 7