Does anybody know the default account at which the crystal reports refers to on a NT4 domain?

I am having issues with regards towards crystal reports enterprise v10

 

we have a domain called i.e. JOEBLOGGS

 

everytime we issue a report using 'unmanaged disk' settings the user has an option to type in a server name\share\folder.  The user HAS FULL access to that area on the network.  When the user submits a report using the default cridentials the report status says running then turns to fail.  the history of the reports shows as:

Status Failed

Printer The instance is not printed

external destination file copy the instance with the filename: filename.ext to the directory file://\\servername\share\folder - \\servername\share\folder

 

error message login error.CrystalEnterprise.diskkunmanaged Logon failure unknown user name or bad password.

 

we can get arround this error if the user supplys their own user account which works sucessfully.  but if the user sets up a re occurance job, they need to then use the default settings and not enter a username or password.

 

is there anywhere on the system that references to an account on the NT Domain?