If you are stuck on 12.0.2000.8 , at least apply (build 12.0.6024.0 ) or the final SP3 CU (build ~ 12.0.6439.10 ). This fixes hundreds of bugs and some known security vulnerabilities.
So if you see 12.0.2000.8 , you are looking at a without any service packs. Microsoft SQL Server 2014 -12.0.2000.8- Key -...
Suggested timeline (example)
Appendix — recommended commands and checks If you are stuck on 12
Are you looking to or retrieve a key from a server that is already running? How to Find Your Existing Product Key
: It is highly recommended to use Mixed Mode so you can use both Windows accounts and the sa (system administrator) account. 🔑 Key & Edition Management
: These require unique keys provided at the time of purchase through the Microsoft 365 Admin Center or authorized retailers. How to Find Your Existing Product Key