Group policy not available after primary domain controller failed

Are you going to fix the PDC emulator? if not you need to seize all its roles to another DC

ou will now need to “seize” the FSMO roles there are 5 FSMO roles which are

·      Schema master - Forest-wide and one per forest.
·      Domain naming master - Forest-wide and one per forest.
·      RID master - Domain-specific and one for each domain.
·      PDC - PDC Emulator is domain-specific and one for each domain.
·      Infrastructure master - Domain-specific and one for each domain.
5.      To do this you need to use the “ntdsutil” tool

To move the FSMO roles from one computer to another, you can use two different methods. The first method is a transfer and is the method that is recommended. You can use the first method if both computers are running. Use the second method if the FSMO roles holder is offline. The second method requires you to use the Ntdsutil.exe tool to seize the roles.

Note Only seize the FSMO roles to the remaining Active Directory domain controllers if you are removing the FSMO role holder from the domain or forest.

To seize or transfer the FSMO roles by using Ntdsutil, follow these steps:
1.      On any domain controller, click Start, click Run, type ntdsutil in the Open box, and then click OK.

Note Microsoft recommends that you use the domain controller that is taking the FSMO roles.
2.      Type roles, and then press ENTER.

To see a list of available commands at any of the prompts in the Ntdsutil tool, type ?, and then press ENTER.
3.      Type connections, and then press ENTER.
4.      Type connect to server servername, where servername is the name of the server you want to use, and then press ENTER.
5.      At the server connections: prompt, type q, and then press ENTER again.
6.      Type seize role, where role is the role you want to seize. For a list of roles that you can seize, type ? at the Fsmo maintenance: prompt, and then press ENTER, or consult the list of roles at the beginning of this article. For example, to seize the RID Master role, you would type seize rid master. The one exception is for the PDC Emulator role, whose syntax would be "seize pdc" and not "seize pdc emulator".

Note All five roles need to be in the forest. If the first domain controller is out of the forest then seize all roles. Determine which roles are to be on which remaining domain controllers so that all five roles are not on only one server.

Microsoft recommends that you only seize all roles when the other domain controller is not returning to the domain, otherwise fix the broken domain controller with the roles.

If the original domain controller with the FSMO roles is still online, transfer the roles. Type transfer role.
7.      After you seize or transfer the roles, type q, and then press ENTER until you quit the Ntdsutil tool.
Note Do not put the Infrastructure Master role on the same domain controller as the global catalogue.
http://support.microsoft.com/default.aspx?scid=kb;EN-US;197132

To check if a domain controller is also a global catalogue server:
1.      Click Start, point to Programs, point to Administrative Tools, and then click Active Directory Sites and Services.
2.      Double-click Sites in the left pane, and then browse to the appropriate site or click Default-first-site-name if no other sites are available.
3.      Open the Servers folder, and then click the domain controller.
4.      In the domain controller's folder, double-click NTDS Settings.
5.      On the Action menu, click Properties.
6.      On the General tab, locate the Global Catalogue check box to see if it is selected.
*****References*****

Using Ntdsutil.exe to Seize or Transfer FSMO Roles to a Domain Controller
http://support.microsoft.com/?kbid=255504

Windows 2000 Active Directory FSMO Roles
http://support.microsoft.com/default.aspx?scid=kb;EN-US;197132

Flexible Single Master Operation Transfer and Seizure Process
http://support.microsoft.com/default.aspx?scid=kb;EN-US;223787

Thanq