I don't want to physically destroy or nuke the drive (have done that many
times) but just to removed personally info so that anyone else would
still carry on using the same computer but without traces of last
person's 'present'
There are tons of cleanup utilities found by Googling. The problem is
that a lot are crap or they don't look everywhere, especially because
everywhere depends on which programs you use and no cleaner handles them
all. Even CCleaner (CrapCleaner) will do some of the cleaning that you
want but is not 100%.
You might want to look into using VMWare Server (free) but you will need
another license for Windows to have a legitimate copy running in a virtual
machine. You do a fresh install of the OS, updates, and anything else you
want in the "base state" for the virtual machine and then save a snapshot
(and lock it to prevent accidentally overwriting it since the free version
only lets you save 1 snapshot). Then pollute however you want. When you
are done, revert to the snapshot and everything is exactly back to that
base state. You could use Virtual PC (free) but it doesn't have the
snapshot feature of VMWare Server; however, you could emulate the snapshot
feature by getting to a base state and then saving the folder where are
the VM files to a backup location and then replace them when you want to
wipe the VM back to that base state.
If you don't want to buy another license of Windows (so you are legit)
then you might want to look into save-state products, like Microsoft's
SteadyState (free) or ShadowSurfer (no longer free, or its big brother
ShadowUser that was never free). Basically they record the incremental
changes to your hard drive while they are active and will remove them when
you reboot so the hard drive is [logically] back to the prior state.
Of course, you could save an image of your partitions or disks and then
restore them to wipe out all changes made after the image got created but
that is a lot of time to restore from the image to get back to the base
state.