Chances are good that rundll16.exe is spyware, a virus, or malware of some type. It is essential that you delete this process from your computer as soon as possible.

Trojan.W32.Nyxem is a type of malware, and rundll16 is linked to it. Adware and malware can be very tricky. Malware creators know their files will be removed if found, so they sometimes give the files names that are similar to known essential files.

A good way to ensure that you only remove harmful files is to use Computer Associates's free scan of your computer.

Since rundll16.exe is running on your computer, you'll probably come across more adware if you do a good search. Get a free scan of your computer by clicking this link.