Access Windows Share under Network Service account

Question

I have two computers with Windows Server 2003. One computer has some shared folders on the network, and the other has a Windows Service (written in C#, running under the Network Service account) that needs to access those shared folders.

The following code works fine as a logged-in user, but throws an exception when executed under the Network Service account.

File.WriteAllText(@"C:\temp\temp.txt", File.ReadAllLines(@"\\NetworkServer\Test\test.txt")[0]);

The exception message is Logon failure: unknown user name or bad password. How do I get this code to work under the Network Service account? Is it a setting in Windows Server 2003, or do I need to add some code to this to make it work?

Answer 1

On the network share, you'll need to add permissions for the "Network Service" account on the server running the service. While this will work, @nicholas points out that this may provide an overly broad group of users access to the share.

Another option, and in my opinion the better option, is to create a domain account and then give that account read/write permission on the share. Then you configure the service to "run as" the domain account with proper permissions.

Answer 2

@Nate's answer is either incorrect or is unclear, as far as I can tell. It doesn't explain how Network Service authenticates on the network.

Network Service account has very limited privileges on a local system, it presents the computers's credentials on the network. So if you need to access a network resource (e.g. a network share) under Network Service account, you have to grant access to the computer's account where the service works.

Providing local Network Service account with access to a network resource won't work at all, you'll keep getting authentication / authorization errors.

See MDSN "NetworkService Account" reference.