I'm sorry you are having problems with installation.
Not sure if you have purchased the download from Costco as an 8 pack, as you mention activation code, so if that is the case, then please uninstall the original version, reboot your computer and use this link: https://turbotax.intuit.ca/x/offers/turbotax-standard.jsp?src=care&cnm=care_fy18_tto_8 using the activation code given with your original purchase.
If that is not the case, then use this link to download 2018 TurboTax software after uninstalling and rebooting: https://turbotax.intuit.ca/product/download/index.jsp using the IKC (21 digits) given with the original purchase.
Furthermore, if needed please see link below to have one of our support agents assist you personally:
I want to talk to someone. How do I phone you?
