Have you tried this: From the unzipped readme file
"Windows2000/XP/Server2003/Vista/Server2008 driver
If you are installing this product at the first time, please follow these
steps;
* Make sure to close all applications before installing.
-1 Start Windows and log on as Administrators or Power Users.
-2 When using a driver downloaded from the Internet:
After downloading the driver from the Internet, extract the file(s)
to a folder of your choice.
-3 From the [Start] menu, point to [Settings] or [Control Panel], then
click [Printers] or [Printers and Faxes]. In the printer folder
double click [Add Printer] (it may be in [Printer Tasks]), and click
"Next >".
-4 Follow the Wizard guidance and select a printer connection method
(My Computer or Network Printer Server / Local or Network Printer),
then click "Next >" to continue.
-5 The following explanation applies when the user has selected a
[Local] connection method. Please select the port to connect the
printer, and click "Next>" to continue.
-6 Specify the folder of the driver files.
A) To install the downloaded driver, click [Have Disk] then [Browse]
to locate the folder where you had extracted the downloaded
driver, from this folder select Disk 1, then click "OK".
B) To install from the CD, insert the CD-ROM into the CD ROM drive,
[Have Disk] button in "Manufacturers:" / "Printers:" window, then
enter the path (e.g. D
DRIVERS\PCL6\XP_VISTA\DISK1\) of the
designated drive then click "OK". (You can also navigate to the
drive by clicking the [Browse] button.).
-7 Select the printer to use. After selecting, click "Next >".
-8 Specify printer name. And if you want to use installed printer as
the default printer, check "Yes". After specifying, click "Next >".
-9 If you want to share installed printer with other network users,
indicate and set sharing. After above, click "Next >".
-10 Print test page to confirm that the printer is set up properly.
Check on "Yes(recommended)", then click "Finish", and finally, the
installation is completed.
After completing above operation, you can use PCL printer driver for
Windows 2000/XP/Server2003/Vista/Server2008.