I don't believe XI R2 was supported on Windows 7, but it's been a while now since XI R2 has been out of support for 4+ years now. It may have been the last version that was supported on Windows 7...
From what I sort of recall is the AD server is either not running or possibly there are some bad Accounts that need to be cleaned up so BOE can begin importing the users into the CMS Database...
Don