Bilateral file sharing always fails, regardless of type of connection

I have a Sony Vaio running Windows XP Home and a Dell XPS, also running Windows XP Home. The Vaio can see the Dell and access the files on the Dell. The Dell can see the Vaio but can't access the files, even though sharing is enabled. All computers are on the same workgroup. I have a Microsoft Wireless 54G Broadband Router. A friend has a Gateway with the same router - same problem. I tried connecting the Vaio to the Dell with an Ethernet cable - same problem. I tried disabling the internal wireless link on the Vaio and using a 54G wireless card in the PCMCIA slot. It always behaves the same. It says I don't have permission to access the files on the Vaio. Calling Microsoft (where you seem to get connected to India) is useless. I spent 4 hours one day with Microsoft support and got nowhere. They told me I should stay home from work so Redmond could call me during the week!

It would seem that if this is related to Windows XP Home capabilities, you couldn't ever see shared files on another computer on the network, but you can. My laptop can see the Dell Tower's files, but not vice versa.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
DWORD KEY "restrictanonymous" = 0

Then reboot.
was suggested in another thread. I found I had to do:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
DWORD KEY "restrictanonymoussam" = 0

because after a reboot, "restrictanonymous" always seemed to get set back to 0. Still seems to work for me. I'm not sure what the difference between the 2 keywords is.

Several threads split and merged.

But it appears that you've now been able to solve your own problem. I've added that extra information to the sticky though.