We currently use 2007 exchange with virtual desktops. We recently had to delete the .NK2 file when we updated our exchange server. We now have to again delete the .NK2 file however it is nowhere to be found. We've done multiple searches even through DOS and we are looking for hidden files etc. Basically, it appears that the file just doesn't exist. We are using virtual desktops, however I do not believe this is the problem as once we log out of the virtual machines they are scrapped.