Missing space on second hard drive
I have a second hard drive in my PC which I use just to store files/backups etc (ie no operating system on this drive). I had saved a large 7gb file to the drive and having just deleted it have found that the amount of free drive space has not returned to the original amount (before the file was created). The missing space seems to equal that of the file I deleted. The file was too large for the recycle bin and was permanently deleted by Windows (XP Pro). Can anyone explain why this has happened? I have tried a defrag and also a program called 'Eraser' to erase unused space. I have copied the files from the drive elsewhere and then attempted a reformat but there always seem to be some files still in use by Windows and it won't let me reformat. Attempting to delete the files gives a similar warning from Windows. I have tried closing down as many processes as I dare and still something (what, I don't know) is reported as being in use. Some of the files/folders are shared on a home network but I make sure they are not in use when I try to delete/reformat. How I can get Windows to report the correct amount of remaining free space on this drive? Is there a method which does not involve deleting the existing files and/or a reformat?
Thanks, in anticipation of an answer that helps.