To reinstall Paprika you just need to re-download the installer from our website, and then use your existing license key to reactivate the app. The version you need to download depends on what version you originally purchased.
If you originally purchased a license key for Paprika 3, download the Paprika 3 installer here:
https://www.paprikaapp.com/downloads/windows/latest/PaprikaSetup.msi
If you originally purchased a license key for Paprika 1, download the Paprika 1 installer here:
https://www.paprikaapp.com/downloads/windows/v1/PaprikaSetup.msi
If you have forgotten your license key, you can request it here:
https://www.paprikaapp.com/license/forgot/
If you originally purchased Paprika 1 and would like to upgrade to Paprika 3 instead, you can request a discount code towards the upgrade price by filling out this form:
https://www.paprikaapp.com/license/upgrade/
Once you have reinstalled and reactivated Paprika you will be able to login to your Paprika account to restore your data, which can be done from Paprika's Settings -> Cloud Sync. (Assuming you previously set up a Paprika account on your old computer. If not, you should set up an account so you can sync your data to the new app.)