I have installed the Desktop version (which I downloaded from TurboTax.ca) on one system. When my son downloads and installs on a 2nd system (I am licensed for 3 as stated above) using the same license code, he receives Error code 603. Something here is amiss. How do I get past this error?

@SaanichGAS Your son has to log into the same account that you used when you first used your licence code. 

I bought a new computer, and try to active : 2025 premier desk version to this new computer.it says code has been used,  what should I do to get it working on my new computer

I bought new computer, and use same account , after I download to my new computer,  it already showing access key code and saying it has been download,  that is final, i cannot do anything .  how do i do i get it going 

Same issue; successfully logged onto my Intuit account on my daughter's computer , but got a message saying "Something's not right - try re-entering your code". 
This is a very problematic setup!

@YOW18 Are you using a Windows OS? You have installed the desktop version on how many devices or how many times? 

i just bought a new computer using window 11, it is replace of my older computer using window 10.  when I bought TURBO TAX desk version in Jan 2025 , i download to old computer, so it is only loaded to one computer, Now I bought a new computer, that is 2nd devise,  buy key code does not let me use it