i am tried to search your problem in net , i got the link where they said that, it is a kind of virus, i am also not familiar this kind of virus. you can check this link also.
My father is notorious for getting viruses on computers. This visit home, I downloaded Malwarebytes and cleaned up his popups. We also updated Java. The computer (a Compaq laptop with XP SP2) was turned off and on a few times throughout the rest of the day, however, upon turning it on the next day, the error "The application or DLL C:\windows\system32\gadagore.dll is not a valid Windows image. Please check this against your windows diskette." pops up for every program attempted to be opened.
I did extensive research on the string "is not a valid windows image...." and got a plethora of answers, none of which worked. I searched gadagore.dll and got barely anything, half of the anythings being in other languages.
We eventually gave up and did a complete reformat, yet, the error is still popping up.