I always purchased and used the desktop version, I have lost my older Ttax program files , how can I get back into them to adjust some older returns for reassesment?

Troubleshooting

You can download older versions of TurboTax Desktop edition here: Where can I download the Desktop edition of TurboTax?

You may also need this TurboTax Canada FAQ: What if I have trouble with my licence code while setting up TurboTax Download?