You've not said what happens when you try to print. e.g. what, if any, error message do you get?
The most likely causes of being unable to print are as follows:
1. No power to printer or no connection from PC. (Check power leads, switches & cables).
2. Major failure with the printer. (That means seeking the services of a dealer or buying a replacement printer).
3. PROBABLY THE MOST LIKELY CAUSE: The printer driver is corrupt. Simply reinstall the driver from the installation disc and everything should be OK. (If you're not sure which bit of the installation procedure actually installs the driver, simply repeat the whole lot).
Chris