The Office 2000 SR-1 administrator updates (O2KSR1aDL.exe) is no longer available on the Microsoft Download Center. This is because Office 2000 extended support expired July 2009:
http://support.microsoft.com/lifecycle/Default.aspx?p1=2484
If you really need this file, we suggest checking in with one of the community newsgroup to see if someone there can help you out. Sorry for the inconvenience!
- Cat