After only just a little over a month on the market, Microsoft released on 3/19/02 Service Pack 1 to the .NET Framework. According to the on-line Microsoft documentation, there were three fixes and change to the “Default Machine Level Security Policy. The update is almost a 6MB download.
If you use the use the Windows Critical Update Notifier, then it will install the update for you. Otherwise you can click here to download the update.