"\\CPU is not accessible" error when I try to access another compu

[rexamillian]

I have a home network set-up through a Belkin Wireless Router with three
computers connected to it.
CPU1: Desktop PC - Windows Vista Home Premium SP1
CPU2: Laptop - Windows Vista Home Premium SP1
CPU3: Laptop - Windows XP Professional SP2

Using 'view computers and devices' on the Vista computers, and 'show
workgroup computers' on the XP computer, the following occurs:
CPU1 displays only CPU1 and CPU2 - but is denied access when double-clicked
(therefore, CPU1 is unable to access CPU2 or itself) - CPU3 is not visible
and not accessbile
CPU2 displays CPU1, CPU2, and CPU3, and can access all
CPU3 displays CPU1, CPU2, and CPU3, and can access all

Okay... so here's what I've tried...
- All are on the same workgroup
- All can ping eachother
- I've tried \\CPU1 and \\CPU2 and \\CPU3 from CPU1, but neither can be found
- Checked winsock for errors
- Enabled NetBIOS over TCP/IP
- Disabled all Firewalls
- All computers have the same DNS, which is the IP of the Router.
- In Sharing Rules, I've given each CPU access to Everyone.
- File and Printer Sharing is checked on all CPUs.
- Network Discovery is checked on both Vista computers.
- At first I had CPU1 on a static IP, and it wasn't listed in the Router's
DHCP list, but I now have it as a Dynamic IP, and it is a listed DHCP.
- No 3rd Party firewalls. Just Windows Firewall, and AVG Anti-Virus Free.
- Service.msc confirms that Windows Firewall is disabled.
- Beaten my head against the desk.

Please help me access my computers from CPU1.

 

[Smithsonian]

Is discovery on.
If you right click on network connection icon and click network and sharing
center, does it say that network discovery is not on. If it does you need to
enable that.

 

[rexamillian]

Thanks for your response.

As stated in the list of things I've already tried... "Network Discovery is
checked on both Vista computers".

Any other ideas?

 

[Smithsonian]

Is CPU1 detecting other 2 computers?

Thanks for your response.

As stated in the list of things I've already tried... "Network Discovery
is
checked on both Vista computers".

Any other ideas?

 

[rexamillian]

No... CPU1 only detects itself and CPU2... but can't access either.

 

[Smithsonian]

Are the sharing settings the same on all the computers
Sorry for being a bit late with a answer. Im playing platform racing

 

[Julian]

Have you turned off IPv6 on the Vista machines?

Have you tried beating your head against the wall? ( usually comes next
for me...)