A couple of software related questions

A couple of quick questions for the tech gods here.

I have an old PC that I wish to sell.

Before I sell it I need to make sure that any personal data on the HDD is unrecoverable.

I know that a standard delete is not sufficient, so I have downloaded a file shredding programme to deal with the existing files, what I am worried about is the free/unallocated space on the disc, where data from files I have previously deleted might be lurking.

Can anyone recommend a free software tool to clean these areas too?

I have found 12ghosts shredder which seems to work, but it keeps coming up with pop-ups exhorting you to buy the product, and requires you to click before it will continue. Hence I will be stuck at my computer for however long it takes to sanitise the 60 odd GB of free space on the disc!

Also can anyone tell me why my external hard drive, which I use for video and music files, is showing an area of 20 or so GB of "reserved system space" when I analyze it with Diskeeper lite, and tells me there is less than 6% free space when windows tells me that there is mor elike 40% free space? Is there a way to remove this reservation so I can defrag the drive properly?

Many thanks.

Scoobs

 

This is my choice for free space cleaning.

http://www.worldssp.net/software/Cleaner.htm

Cleaner 1.1 at the top of the page.

 

Thanks BB, looks interesting!

It's a bit simple compared to the 12 ghosts software, no options to set number of passes or anything like that but if it gets the job done and I can set it to go and leave it then I'll be a happy man!