Many people probably encountered This message appear when you click on the Control Panel Items, or right click on my computer.
Reason 1: You have a virus or trojan
Reason 2: Your antivirus has deleted rundll32.exe because your PC was infected by a malicious program
Reason 3: This is a false error message and some malicious program is going to trick you that way.
What is rundll32.exe?
rundll32.exe is a System required process and it shouldn’t be disabled. Please note: rundll32.exe is needed for essential applications to work properly
To resolve this issue, follow these steps:
1. Put the Windows XP CD ROM disk in the CD ROM drive.
2. Click Start, and then click Run.
3. Type expand X:\i386\rundll32.ex_ c:\windows\system32\rundll32.exe in the Open box, where X is the letter of your CD ROM Drive.
4. Restart the computer.
Or an easy way is to copy that file from another computer in C:\Windows\System32\rundll32.exe and replace back.
It should work for you.