this is an easy one.
go threw all the files and make sure every thing points to the right directory
i.e
Dir=C:\mirserver\DBServer\FDB\
IdDir=C:\mirserver\DBServer\FDB\
HumDir=C:\mirserver\DBServer\FDB\
FeeDir=C:\mirserver\DBServer\FDB\
BackupDir=C:\mirserver\DBServer\Backup\
ConnectDir=C:\mirserver\DBServer\Connection\
LogDir=C:\mirserver\DBServer\Log\
if your running your server from a diffrent directory make sure you change your path.
this is the problem you have.
you probs have a second hdd which the server is run off so change it to D: instaed of C: