1. Download the latest service patches, security patches and hotfixes for your version of Windows via the Windows Update service. Click on 'Start,' 'All Programs,' 'Accessories' and 'Windows Update' in Windows XP or 'Start' and 'Windows Update' in Windows Vista and Windows 7. Select all important/critical downloads, and wait for Windows to download and to install the updates. You may have to restart the computer several times, depending on the number of updates available.
2. Download and install a newer version of the non-Microsoft software if available. Access the integrated 'Check for updates' feature, or visit the software vendor's website to install the latest version.

3. Install or turn on your firewall if it is not currently enabled. Block the ports that your potential buffer overrun exploiters will request when transmitting malicious data. Switch on the Windows Firewall by clicking 'Start,' the 'Control Panel.' Click on 'Classic View' in the left column if applicable, then double-click 'Windows Firewall.' Click on 'Turn Windows Firewall on or off' in the left column in Windows Vista and Windows 7, or click 'On' in the 'General' tab in Windows XP. Select 'On' or 'Turn on Windows Firewall' in Windows Vista and Windows 7, then click 'OK.'