At the risk of beating a dead horse, I'm going to talk about DST and link to some tips and articles.
There's also been much made about the $4,000 patch from Microsoft, and I want to clarify a few things. That $4,000 is the full suite of DST patches from Microsoft for an unlimited number of servers and client machines running old out-of-support software. That patch happens to include the Exchange Server 2000 and 5.5 (1997) patch as well. There are also free tools like TZEdit and automated scripts available for Windows 2000 that you can use to automate the entire update for all of your Windows 2000 machines. Compare this with Apple, which doesn't even offer patches for DST for any version of OS X from before 2003.