Not only that, but you didn't place hijackthis in a non Temporary folder on the C Drive, if warez made a mistake, we wouldn't have been able to back it up.
( I know He wouldn't have made a mistake)
Post a hijackthis log anyways I don't trust system restore.
Place the program file of hijackthis in a folder by itself on the C Drive.
It cannot be a temporary folder.