AllainU 0 Report post Posted July 25, 2018 Hello @rexmckar, Thank you for reaching out to us through our Community Forums! Since you purchased Nitro Pro 11, you may use these direct links to reinstall it after uninstalling Nitro Pro 12 and rebooting your machine: x64 http://install.nitropdf.com/professional_1108470/en/burn/nitro_pro11_ba_x64.msi x32 http://install.nitropdf.com/professional_1108470/en/burn/nitro_pro11_ba_x86.msi After installation, you can activate by opening Nitro Pro, clicking on the Help tab > About Nitro Pro > Activation and entering your Nitro pro 11 serial number. Thanks for choosing Nitro Pro and I hope this helps! Share this post Link to post Share on other sites