Patches and Service Packs
Always install the latest service packs and patches of the
operating system as well as of applications. Most software vendors have
mailing lists or news letters that alert you about patches and updates. Be
sure to subscribe to these.
releases security updates in-between service packs. Don't wait for the next
service pack to become available. It may never come.
In a small network, you can use the Windows Update
software to automate software updates from Microsoft. There is a bit of
controversy about Microsoft installing software to your computers without
your knowledge, but you can configure Windows Update to prompt you before
Whatever you do, get those security patches.
Typically, you only have a couple of days to get your systems patched up
before there is an exploit out there on the 'net. Sometimes you only have
hours from the time the exploit is made public.