I just bought a new printer. Should I uninstall the old printer driver?
The Decision: Leave it Alone or Uninstall Old Printer?
While it's not mandatory to uninstall an old printer driver, it may be beneficial to do so. After all, why clutter up your computer with a bunch of unused drivers? On the other hand, if you think that you may use the old printer from time to time or your computer is running just fine as it is and is not short on resources, I'd leave it alone.
Keeping the Existing Printer Driver
If you decide to keep the existing printer, you'll need to set your new printer as the default printer so that when you go to print a program it will be automatically selected. Once the new printer is installed, go to Control Panel and click on Printers. Right-click the new printer and choose "Set as Default Printer."
Now, should you ever need to use your old printer, you can do so without having to reinstall it. Simply plug it in and choose the old printer from the drop down list within the Print Document dialog box.
Uninstalling the Old Printer
If you decide that you have no need for the old printer (such as if it's broken and long since recycled), then uninstalling it will minimize the clutter. Uninstalling a printer and its driver is easy to do and you shouldn't have any adverse effects from doing so. Go to Control Panel and click on the Printers icon. Find the old printer in the list, right-click it, and choose Delete.
In addition to the printer, your computer may have additional printer software that was installed with your original printer installation. For example, a printer diagnostic utility, an updater, or image editing software might have been installed with your printer. Removing these components is easy to do. Go into Control Panel and choose Add and Remove Programs (Programs and Features in Vista) and remove any unwanted programs related to your printer. You may even see the printer's printer driver listed here, so remove that as well.