The data you are looking should not, by default, be located in "C:\Documents and Settings\Default User". That is the location of the default user profile, which is the template for new user profiles. Its only function is to be copied to a new folder for use as a user profile when a user logs onto the computer for the first time.
If the service is following Microsoft's guidelines, it will be storing data in
the application data folder (%APPDATA%) or the local application data folder (%LOCALAPPDATA% on Windows Vista and later). It should not use the My Documents or Documents folders, but you might want to check there as well.
On a typical installation of Windows XP or Windows Server 2003, check the following locations for application data for programs running as Local System (NT AUTHORITY\SYSTEM):
- C:\Windows\system32\config\systemprofile\Application Data\Vendor\Program
- C:\Windows\system32\config\systemprofile\Local Settings\Application Data\Vendor\Program
- C:\Windows\system32\config\systemprofile\My Documents
On a typical installation of Windows Vista and later versions, check the following locations for application data for programs running as Local System (NT AUTHORITY\SYSTEM):
Of course, substitute the appropriate vendor name and program name for Vendor and Program.
[Edit - for bricelam]
For 32 bit processes running on 64 bit windows, it would be in SysWOW64.