.NET Framework 2.0 SP1 requires that Windows 2000 Service Pack 4 be installed on your computer before you install .NET Framework 2.0 SP1. You can download and install this service pack from http://windowsupdate.microsoft.com/. After you install this service pack, you are required to restart your computer. .NET Framework 2.0 SP1 setup will not automatically restart. To restart .NET Framework 2.0 SP1 setup, double-click setup.exe on the CD, DVD, or network share you installed from or click the appropriate link on the download Web site.
Note: It is highly recommended that you regularly check for and install updates for your operating system. To search for operating system updates, see http://windowsupdate.microsoft.com/.
Service packs are the means by which product updates are distributed. Service packs can contain updates to improve system reliability, program compatibility, security, and more. For more information on Microsoft Service Packs, see http://support.microsoft.com/default.aspx?scid=fh;EN-US;sp.