Step 4: Start Windows in Selective Startup mode Make sure you know whether your PC is running the 32-bit or 64-bit version of Windows. Step 3: Make sure you’re installing the right version for your operating system Type MSIEXEC /REGSERVER, and then press Enter. In Windows XP, click Start, click Run, type cmd, and then press Enter. Right-click Command Prompt, and then click Run as administrator. In the Start Search box, type command prompt. In the Search programs and files box, type command prompt. On the Services page, on the File menu, click Exit. If Start is unavailable and the Stop and Restart options are available, this tells you that the service is already started. Right-click Windows Installer, and then click Start. In Windows XP, click Start, click Run, type services.msc, and then press Enter. In the Start Search box, type services.msc, and then press Enter. In the Search programs and files box, type services.msc, and then press Enter. Step 2: Ensure that the Windows Installer service is running If this doesn’t resolve the issue, continue to the next step. Install Microsoft Security Essentials again.

Completely uninstall any existing Internet security programs.Step 1: Remove antivirus or antispyware programs Sometimes installations fail for an unknown reason. It is usually because of some other security program running or missing some prerequisites for installation. Issues encounter at the time of installation of Microsoft Security Essentials

Microsoft essential 32 bit