I am using the following steps to change the settings for dcom. The 'Edit Limits' button is greyed out. I am logged in as a local admin and the firewall is disabled.
To allow anonymous remote access in DCOM:
1.From the Start menu, click Run and type Dcomcnfg.exe.
2.In Component Services, click Console root, click Component Services, click Computers, and then click My Computer. On the Action menu, click Properties.
3.In the My Computer Properties dialog box, on the COM Security tab, in the Access Permissions section, click Edit Limits.
4.In the Access Permissions dialog box, grant Anonymous Logon allow Remote Access.