Here are some steps to correct horizontal or vertical streaks in your prints:

1. Check your toner cartridge’s condition and replace if necessary.
2. Clean your printer’s rollers according to the manufacturer’s instructions.
3. Check that no foreign objects, such as paper clips, are obstructing the printer’s feeder tray.
4. Adjust the paper settings to account for the type and weight of the paper being printed on.
5. Perform a calibration test on the printer.