How to Fix Rundll32.Exe for Free

1. Boot up Windows in “Safe Mode” by repeatedly pressing the "F8" button on your keyboard while Windows is loading up. The “Advanced Options” menu will open. Select the "Safe Mode No Networking" option, then press the "Enter" key.
2. Open and run your antivirus program by double-clicking on the program’s desktop icon. Click the “Full Scan” button to scan all of your files, folders and programs on your hard drive for malicious software. If any malicious software is detected, delete them and reboot your computer.
3. Insert the Windows system CD into your computer after Windows has begun.
4. Replace or copy over your old “rundll32.exe file.” Click the Windows desktop “Start” button and click the "Run" icon to begin, and open the “Run” prompt.
5. Type the following (without quotes) into the “Run” text field box:"expand (place the letter of your CD drive here):\i386\rundll32.ex_ c:\windows\system32\rundll32.exe"Click the "OK" button. This installs the original rundll32.exe file from your Windows CD. Afterwards, reboot your computer system.