windows 7 - I can't delete a file, it's in use by the system... But it isn't

Possible Duplicate:
I can't delete a file - even when using unlocker

I tried all the tools from the question How do I delete a 'locked' file?, and they didn't help.

All the software suggested to download attempted to unlock my file, but they all failed. Additionally, booting into safe mode still didn't solve my problem.

When I try to delete the file (an ISO image that I created of the Windows 8 Install Checker), I get this error:

I obviously can't end System.exe, that'd crash my computer. I've been trying to remove it daily, and it won't let me delete it, even right after a restart.

It's stored on my desktop, and I can't move it, because I get that error.

Answer

You can schedule the file to be delete the next time you boot. It will be deleted early in the boot process, before any programs access it. I prefer BitSum’s tool movelater; for example:

movelater C:\Users\Chippery\Desktop\win8install.iso /d

You can also use Sysinternal’s MoveFile:

movefile C:\Users\Chippery\Desktop\win8install.iso ""

That takes care of the file, but that it is always locked by the system process when you boot indicates an ongoing usage which may cause problems if you delete the file and the system tries to access it.

Because the system process is the one locking it, it is likely a driver that is using it. Because it is an ISO file, it seems that you have mounted the disc image in a program that is using a driver to emulate a CD/DVD.

As curmil suggested, it is best if instead of just forcing a delete of the file on boot, you run the mounting program and unmount the image and you should find that the file is no longer in use. If it is, then a reboot should free it up, without needing to resort to the above tools.