There can be different reasons for changing the directory for the Print Spooler Service on a print server:

• There is not enough room at the default location (%systemroot%\system32\spool\printers) causing the large print jobs to fail
• There is a faster HDD available which can improve the performance of the printing
• There is a need to distribute the print jobs for different printers on different HDDs

One can change the default location of the spool folder :

1. Control Panel -> Printers
2. File-menu -> Server Properties
3. Select the Advanced-tab and change the "Spool Folder"

One can also change the default location in the registry:

[HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Control \Print \Printers]
DefaultSpoolDirectory =

One can change it for a specific printer:

[HKEY_LOCAL_MACHINE \SYSTEM \CurrentControlSet \Control \Print \Printers \{Specific Printer Id}]
SpoolDirectory =

Note if the contents of the spool directory becomes corrupted then it can keep the Print Spooler Service from starting. Solve this by deleting/moving the contents of the printers spool directory. More Info MS KB250038

More Info MS KB123747
More Info MS KB314105