What kind of returns?

This is a community forum of tax professionals trying to support each other in the use of a particular software for professional income tax preparer's. Your initial question sounds like you may have ended up in an unintended area.

The software you used to print W2s most likely has W2C available.  IRS has the instructions for completing a corrected W2.  Any other taxing authority - such as state unemployment should also have information available on their website on how to amend.

C-corp

C Corp is the entity type. It doesn't use a W2.

Are you using ProSeries to prepare the 1120?

Or, are you asking a Payroll reporting question? Because ProSeries is Income Tax Preparation.