Here are a number of proactive ways to prevent low-risk business disruptions which typically present little if any legal or financial downside.

Anti-virus software - to protect against Web or e-mail based viruses that can corrupt your system. Also prevents installation of Trojan programs, which can gain control of your servers or workstations.

Anti-spam software - removes unsolicited e-mail, often of a commercial nature, sent indiscriminately to your users.

Anti-phishing software - warns users when e-mail messages looking as if they came from a legitimate source, such as an online store or bank, but are actually from a fraudulent source The e-mail tries to get users to enter sensitive information to steal their identity.

Anti-spyware software - to prevent companies from collecting personal information from you without your knowledge.

Companies tend to focus attention on securing the perimeter of their network while forgetting that the most valuable assets are really on the inside:

Inventory - to tell you what to protect. Your assets include computers, network devices, software and data.

Password policies - Implement password complexity requirements. Require users to change passwords on regular intervals

Firewall implementation - Incorporate stateful packet inspection, to ensure the validity of every connection traversing all firewall interfaces

Monitor Logs - System logs, application logs etc…
Automatic system and application software updating and patching
Scheduled network scans to find and eliminate possible security exposures

Shares and Shared Resources - decide what to make accessible and who should be able to access it.

System Documentation - create and maintain network diagrams, system information, Administrative users names and passwords. Firewall user names and passwords.