Enabling "USB Printing Support" in Windows 7

You can add the printer manually via:

1. Control Panel -> Devices and Printers -> Add a Printer -> Add a Local Printer
2. In Choose a Printer Port, select Use an existing port
3. In the drop down menu, select the USB001 or USB002 etc. (Virtual Printer Port for USB)
4. Select Next
5. In the Manufacturers section, select the printer's manufacturer
6. In the Printers section, look for your printer model and select it.

If the printer model is not available, you will need to manually supply the driver.

EDIT

The USB-to-parallel port adapter should have come with a driver. If the driver is not installed, then the device will indeed show up as unrecognized. If you don't have such a driver, please let me know the manufacturer and model of the adapter and I'll try to find one. I'll also need to know whether you're running Windows 32-bits or 64-bits.