Hi everyone! I have Cubase 8 Pro installed on my PC and I just bought Cubase 10 Pro upgrade. Should I uninstall previous Cubase 8 Pro or install the new one above. Please give me the answer. Thanks in advance. Best regards to everyone!
1st post… WELCOME! 
Leave CB 8 on and install CB 10. CB 10 will install as a separate program so you will still have access to CB 8 if you need it. After you are comfortable with CB 10 and it is working well you can delete CB 8 if you want. But, I think many keep the older software on to ensure they have backup plan to open older projects with possible 32 bit VSTs. Also, the actual CB 8 software itself does not take up much HD space. So there is not much space saving in that regard if you delete it.
Regards 