Hi,
You check the disk caching setting in Control Panel/System/Hardware/Device Manager then right click the disk drive and select properties, then select policies and uncheck enable write caching on the disk, then reboot.

>>Run filemon from http://www.sysinternals.com/Utilities/Filemon.html and see what still has it's hooks into it.
>>Also check if caching has been turned back on, the system may not have written the cache back to disk yet.
>
>Well, it seems to be related to IIS, after I shut it down from Services, I was able to have access to the file. I don't know why it is acting like that now. But, this was reproduceable. I did that again in the same simulation after a reboot. This is new since recently.
>
>Where would I go to check for the cache?