Windows – Accessing – Manipulating Administrator shares across windows servers \\computername\c$

Problem:
\\computername\c$ returns "Network Name cannot be found"

I tried using \\computername\c$ as well as well as with the FQDN \\computername.domain.company.com\c$ and the IP address too.

net use * \computername\c$ /user AdminprivilegedUser –> returns "The network name cannot be found"

Computer's in question:

1. WinXPSp2x86 (part of us.company.com on corporate network)
2. WinVistaSp2x86 (part of us.company.com on corporate network)
3. WinServer2003SPx86 (part of uk.company.com on corporate network) – \\computername\c$ -> works!
4. #1WinServer2008R2SP1x64 (part of uk.company.com on corporate network) – \\computername\c$ -> works!
5. #2WinServer2008R2SP1x64 (part of uk.company.com on corporate network) – \\computername\c$ -> doesnt work

[WinServer2003SPx86, #1WinServer2008R2SP1x64 are production servers, #2WinServer2008R2SP1x64 is a staging server]- in case that helps in any information

The computer (client) I am using to access the shares is WinVistaSp2x86.

Edit: Updated with more details

\\WinXPSp2x86 — lists shared files.
\\WinXPSp2x86\c$ — returns network name not found
[UAC – Not applicable | HKLM..LanmanServer.. Autoserver key unavailable]

\\WinVistaSp2x86 — lists shared files.
\\WinVistaSp2x86\c$ — returns network name not found
[UAC – Off | HKLM..LanmanServer.. Autoserver key unavailable]

\\WinServer2003SPx86 — lists shared files.
\\WinServer2003SPx86\c$ — works!
[UAC – Notify me only when programs try to make changes to my computer | HKLM..LanmanServer.. Autoserver key set to 1]

\\#1WinServer2008R2SP1x64 — lists shared files.
\\#1WinServer2008R2SP1x64\c$ — works!
[UAC – Notify me only when programs try to make changes to my computer | HKLM..LanmanServer.. Autoserver key set to 1]

\\#2WinServer2008R2SP1x64 — lists shared files.
\\#2WinServer2008R2SP1x64\c$ — returns network name not found
[UAC – Notify me only when programs try to make changes to my computer | HKLM..LanmanServer.. Autoserver key set to 1]

if I RDP to this 2008 server, and try \\localhost or \\localhost\c$ it shows me the share. However if I do \\servername or \\servername\c$ it would give me a credential prompt window saying 'logon failure or bad password'

I am trying to understand what makes this differenciation between a #1WinServer2008R2SP1x64 and a #2WinServer2008R2SP1x64.

• User Access Control is turned off. (wherever applicable on the above list of computers)
• File and Printer sharing for Microsoft Networks is enabled on the Network Properties on all computers.
• All the computers (as mentioned above) does show their shared files when accessed using \\computername. [They show the shared folders that are located accross multiple drives (C, D, E, F) on the computer.]
• User account used to access all these shares is a part of Administrator group across all these computers.

• Firewall? I dont think it a problem here, since I am able to access the files shared on all these computers and what I am not able to access is the default administrator shares.

• (more information? will be posted on request as I have posted everything related that Iam aware of)

Expected Solution: I want to be able to access the administrator shares across all the above computers. I want to be able to browse the hard drives in those computers via their driverletter$ syntax.

May be I am not understanding how an Administrator share is configured by the operating system or the changes that happen to file sharing when a computer joins a domain. I have tried my best to explain the situation, please request for more information if anything is vague.

I am not an IT Administrator, I do not manage any of them, I am a Developer that mananges applications deployed accross all these servers.

I have provided a subset of the servers, I do have more servers that my application runs on and I want to be able to access all of them using their administrative shares, and I dont want to manually share a particular folder for a particular user or for Aministrator's group, because the folder that I might access may vary. And I dont want to explicitly share an entire drive partition on a server as my IT Administrators will hate it as a prohibited activity. While I do understand their concers, I dont understand how that Administrator share work in some computers (including the production ones).

[Edit: Posting Solution]

tweaking the autoshareserver key on servers and autosharewks key on workstations under the registry entry
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\
enabled the default hidden admin share on the servers and
workstations.

After setting this registry key value to 1, I had to restart the
LanmanServer to view the admin shares.

For disabling them, after setting the registry key value to 0, I had
to restart the Lanman server to see the changes.

However for disabling admin shares on the WinVistaSp2x86 workstations,
after setting the autosharewks to 0 and restarting lanman server, I
had to manually disconected these admin shares from 'compmgmt.msc' |
System Tools| Shared Folders| Shares to disconected the admin shares
and disable them. Else they kept showing up.

Thanks everyone for paying attention to way too many details on this
question.