The System is inaccessible some settings may not be available: Invalid pointer

Hi All,

I have configured my Runtime.exe in 3 machine(A,B,C).
Runtime.exe contains,
a) Runtime
b) Admintool
c) DBmigrate(DB)

so, i have configured like m/c 'A' --> Admintool.msc
      m/c 'B' --> RunTime
      m/c 'C' --> DBMigrate(DB)

Also I have full Admin Privileges on all 3 machines.
After configuring, 
In m/c 'A' i have added new remote server(i.e., m/c B) in admintool.
then i register a new database server. And then I deployed a system in newly register database

After deploying i wanted to configure that system from m/c 'A'.

when i do this i get an below error message in event viewer,

DCOM got error "2147500035" from the computer 'B' when attempting to activate the server:{07DBA4CC-C095-43BD-98C8-B7A971B580B8}

but, Computer 'B' is active and also have full Admin Privileges.

we have used ,

CoCreateInstanceEx( CLSID_RuntimeData, NULL, 0, &si, 1, &mqi ) 

method to create an instance of remote machine, also for COM GUID.
All GUID, host name is completely returning accurately. but still i am facing an above error.  

can any one please suggest me how to over come this error.

Regards,

Tejas