Windows 2000/5.0.2121.1

According to Random_User at BetaArchive, in  in build 2128.1 and higher, there is a reference to Microsoft Windows 2000 Build 2121.1:

[2/2/2000 19:21:43] LogFile Open. [***** Search on FAIL/MessageBox keywords for failures *****]. [2/2/2000 19:21:43] Initial thread locale=409 [2/2/2000 19:21:43] returned from France fix with locale 409 [2/2/2000 19:21:43] OC_PREINITIALIZE:[iis] End. Return=1 (OCFLAG_UNICODE) [2/2/2000 19:21:43] OC_INIT_COMPONENT:[iis,(null)] Start. [2/2/2000 19:21:43] OC_INIT_COMPONENT:9/10/1999 0:00:00 A_______ 5.0.2121.1: 5.00.0984: x86: C:\WINNT\System32\Setup\iis.dll

Source: Random_User @ BetaArchive