In Windows 2003 server , all the domains and subdomains will have the following format of physical path : 

C:\Domains\domain.com\wwwroot (web pages)

C:\Domains\domain.com\db (database)

C:\Domains\domain.com\wwwroot\subdomain_name (sub domain directory)

C:\Domains\domain.com\logs (log files)

For example, you have a domain namely abc.com and a subdomain name test.abc.com , the physical path will be as follow :

C:\Domains\abc.com\wwwroot

C:\Domains\abc.com\db

C:\Domains\abc.com\wwwroot\test