The different measures for preventing virus are:

1. Install quality antivirus:

The users should install professional, business-grade antivirus software on their PCs. Pro-grade antivirus programs update more frequently throughout the, protect against a wider range of threats (such as rootkits), and enable additional protective features (such as custom scans).

2. Install real-time anti-spyware protection:
Use of professional (or fully paid and licensed) anti-spyware programs are required to prevent infections and fully remove those infections already present.

3. Keep anti-malware applications current:
Antivirus and anti-spyware programs require regular signature and database updates. Without these critical updates, anti-malware programs are unable to protect PCs from the latest threats. Computer users must keep their antivirus and anti-spyware applications up to date.

4. Perform daily scans:
Enabling complete, daily scans of a system’s on hard drive gives protection. These daily scans can be invaluable in detecting, isolating, and removing infections that initially escape security software’s attention.

5. Disable autorun:
Many viruses work by attaching themselves to a drive and automatically installing themselves. As a result, connecting any network drives, external hard disks, or even thumb drives to a system can result in the automatic propagation of such threats. The users can disable the Windows autorun feature to avoid.

6. Don’t click on email links or attachments:
Users should never click on email attachments without at least first scanning them for viruses using a business-class anti-malware application. As for clicking on links, users should access Web sites by opening a browser and manually navigating to the sites.

7. Use a hardware-based firewall:
The software-based firewall included with Windows isn’t sufficient to protect systems. For this reason, all PCs connected to the Internet should be secured behind a capable hardware-based firewall.