Windows 7: networking sharing not working

i have been trying to get two computers to network share: one being a laptop with windows vista 32 bit and the other is a desktop with windows xp 64 bit. the laptop is able to see the desktop. however, when i go to "Network" and try to access the files on the desktop comp through my vista machine, i am given an error message saying that "Windows cannot access ***** " with an error code 0x80070035. the error says that the host name is invalid, even though it is the correct name of the xp machine. i should also mention that i have a windows 7 laptop that IS able to network share with the xp machine with ease. both comps have the same workgroup name and the xp machine gives me a similar error message as well. i have tried changing the registry files by following these instructions from a previous thread:



Solution is really easy just modify one key in registry: Back up the registry before making this adjustment...
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
create or modify 32-bit DWORD: LocalAccountTokenFilterPolicy
set the value to: 1

another peculiar thing i have noticed is that each time i go into the "Network" tab on the vista machine, there's a notification saying that network and file sharing has been turned off and that i can turn it on if i would like. the vista machine uses microsoft firewall and defender and also uses an antivirus program called avg antivirus. however, i have disabled the antivirus several times and it made no noticeable changes. on the xp machine, simple file sharing has been disabled as ive heard that might cause issues as well. any help would be immensely appreciated!!