When I used to be a kid instead of formatting I used to delete everything in my hard-disk.
When try to delete all the files from my Windows installed hard-drive some system files remains un-deleted. Even after installing another fresh copy of Windows (without formatting the drive) the files remain there un-deleted and when I try to manually delete them the system says "access denied" (don't remember the error message).
How can I delete these system Files ?
Although formatting the hard drive before an installation of a new Operating System is best and I highly recommend it, you can delete files that windows doesn't want deleted by taking ownership of the file and then deleting it. This is how you take ownership of a file:
Right click the file, select properties, and then the security tab.
Select then Advanced at the bottom of the window and then the tab owner.
Select Edit and then select the user you want to give permission to (either yourself or administrators)
Select Apply and then ok. Select ok and everything else so that all dialog boxes are closed.
Bring up the properties of the file again, and then select edit.
Select either the Users group or the Adminstrators group according to what you selected earlier.
Click the box below "Allow" and next to "Full Control"
You can then delete the files necessary.
I recommend booting from a different disk (CD/DVD or external drive) then you can access the internal hard drive and do as you see fit without windows complaining that files are in use or locked.
