While they didn't release patches for earlier versions of Windows than WinXP, they did provide a tool that makes adding the changes to the Registry much easier than just editing it yourself.
The tool is called TzEdit.exe, and it works fine with Win2k, but I have not tried it with Win98 yet.
Basically you download, un-zip, and run the tool, then select an existing Time zone to edit (i.e Eastern Standard Time).
You tell it when the new Daylight Savings Time starts (in the USA it is 2 a.m. - the Second Sunday of March) and when it ends (2 a.m. - 1st Sunday of November).
Save the changes and you are done with the editor tool.
To make the changes effective, double-click on the clock in your Taskbar.
When the Date and Time Properties Applet opens you must select and apply another timezone (i.e Pacific Standard Time) from the Time Zone Tab, then go back to the Timezone you edited, select it and hit apply again.
The automatic switch of your computer's clock for DST should occur normally from then on for that time zone.
If you move and/or otherwise change time zones, you'll have to edit each different time zone individually.
Please Note: If you use MS Outlook, it must be updated as well, and a separate tool is available to do that as well.
Hope this helps someone...
CptA