When you delete a check, Quicken removes the transaction from the register and recalculates all subsequent balances. You cannot get the transaction back. Consider voiding a check instead.
When you void a check, Quicken removes the dollar amount of the transaction and inserts the word VOID before the payee name. Quicken also adds an R to the Clr field so that the transaction won't interfere with reconciling. If the transaction contains split amounts, Quicken changes each amount to zero.