How to Enable Group Policy Editor

1. Click Start, and then click Run.
2. In the Open box, type mmc, and then click OK. mmc=Microsoft Management Console
3. On the File menu, click Add/Remove Snap-in.
4. Click Add.
5. Under Available Stand-alone Snap-ins, click Group Policy, and then click Add.
6. If you do not want to edit the Local Computer policy, click Browse to locate the group policy object that you want. Supply your user name and password if prompted, and then when you return to the Select Group Policy Object dialog box, click Finish. NOTE: You can use the Browse button to locate group policy objects linked to sites, domains, organizational units (OU), or computers. Use the default Group Policy Object (GPO) (Local Computer) to edit the settings on the local computer.
7. Click Close, and then in the Add/Remove Snap-in dialog box, click OK.

Close all the mmc windows and again start it from run. You can access the GPE now.

Source: www.microsoft.com