Active Directory

I have a child domain with 2 servers in it. I have been having trouble with replications and believe that one server is having hardware trouble therefore the sysvol is not stable. The problem I have right now is that I cannot get into any active directory tools whatsoever. I know this is kind of vague but any help would be appreciated. I have verified time server is running on both and are at same time. I have run secedit to reset security but to no avail.