What Is Rundll32.exe?
Rundll32.exe is an important process of your windows operating system. The process rundll32.exe executes dll files and puts their libraries into your system's memory. Without this process your computer would become instable and very slow.
The process runs from your system directory C:\windows\system32. If it executes or runs from a different location it is most likely a virus or trojan horse. You should scan your computer immediately with a virus scanner. Viruses using the name rundll32.exe are W32.Miroot.Worm. Backdoor.Lastdoor, and Trojan.StartPage (among others).
If a virus, such as the Netsky, destroys your rundll32.exe or, if for some other reason, your rundll32.exe is corrupt or gets accidentally removed, you need to take the following action:
Locate a Copy of Rundll32.exe on Your System
Check if you find a copy of rundll32.exe in the folder C:\windows\system32\dllcache or in C:\windows\ServicePackFiles\i386. If this is the case, go ahead and copy rundll32.exe to the system folder C:\windows\system32
If you don't find a copy on your system, you can try to find the file on your windows installation disks. Lastly, you could simply re-install windows. However, this would be very time-consuming and you might lose all your data. So this would be the last resort.
First of All Run a System Repair Tool to Fix Rundll32.exe
There are various tools available on the Internet that scan, analyze, and fix your computer. Besides fixing your rundll32.exe, these tools will remove any registry errors, remove invalid shortcuts and duplicate files, repair DLL files, and remove startup and runtime errors.