Licensing

Clarify - you have THIN clients logging in to the network or to the Domain Controller via RDS (you SHOULD NOT have a DC as an RDS server, but you need to clarify this).

If it's NOT an RDS server, then Client Access Licenses DO NOT play a role.  In 2008 R2 it's a paper documentation thing - there is no enforcement EXCEPT for RDS.

I would suggest you examine the logs of the DC to see what is happening.

Check and make sure the clients that are unable to login are receiving addressees from the DHCP server.

If not, you may want to re-configure your DHCP lease period to 1 day (8 hours) or less so addresses are not hogged up when not active

Thanks for the replies. Sorry for brief explanation. Basically what happens is there are 20 thin clients. Each set of ten clients are controlled by a 'server' with Windows 7 on but thin-client software that apparently controls them. There is also a domain controller onsite that provides access to resources etc.

So, we have a domain controller > 2 x thin-client servers > 20 clients

Each thin client picks up the Windows 7 desktop from the thin-client servers, thus, thin-client servers are  windows 7 and have thin-client software on, something called vspace, not familiar with it, and the client machines get the same virtual desktop, the domain controller provides access to resources.

The domain controller does not have any thin-client software on but not sure if it should have, but how does the licensing work in this scenario ?

Im confused as the way the licensing works here. Do I need a Windows VDA license ? Where is this installed to ?

Your environment is Ncomputng. Since you are not sure which model you are using i recommend you contact them. They can confirm your environment it and help configure it. You may not need the Windows VDA but CALs instead.

http://www.ncomputing.com/mslicensing

CT