| Full buildtag | 5.5.5111.1 | 
                                
                    | BIOS date | 12/12/1999 | 
                                    
                        | Timebomb | 31/10/2001 (+690 days) | 
                                
                    | Product Key | W7XTC-2YWFB-K6BPT-GMHMV-B6FDY | 
            
         
                    
Notes
            The only leaked Neptune build, includes Activity Centers.
This Microsoft project was never released but some features ended up in Windows XP and above.
NTC Stands for NT Consumer.
Screenshots
The screenshots are provided by KenOath.
1st April 2020 release
On the 1st of April 2020 a new disc appeared which is the best version we could possibly see out of Neptune mostly original.
This is the same build that was given out to external testers on 1999/12/27 as the 6th variant.
        
        
                    
Fixes
            Enable the Activity Centers
Copy 
accore.dll to 
C:\Windows\System32
Run 
regsvr32 accore.dll from the Run window or Command Prompt.
Right-click the desktop and select 
Active Desktop --> Show Web Content
Right-click the desktop and deselect 
Active Desktop --> Show Desktop Icons
Right-click the desktop and select 
Active Desktop --> New Desktop Item...
Click on 
Browse and select 
C:\WINNT\Activity\Start\StartPage\Millennium Desktop.htm
At the top bar click on the 
arrow down and select 
Cover Desktop
        
                    
Screenshots (111)
                                        
                     
                
                            
                     
                
                            
                     
                
            
            
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