Best alternative to recover & secure overwite

A deep scan on just one of my laptop partitions is going to take days, it says, so finding and overwriting sensitive files seems impossible as I really need to use the thing.

So what is the best alternative: format, reinstall OS and all my "live" data (which will overwrite a lot of stuff, right?) then overwriting the free space with CC?

And doing repeated formats - does that make a difference?

Or is there another way?

And what about the paging file? I know it exists but dont know what its for: does it hold data? Will it get formatted then overwritten too if I do it the way I asked?

Thanks

You may as well do a wipe free space on the partition you want to clear, it's as good as anything else. Formatting does not get rid of old data, it's more or less a slightly more thorough chkdsk. The pagefile is not overwritten during either wfs or formatting, as far as I know. You can clean it at pc shutdown by setting HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management\ClearPageFileAtShutdown to 1, or at least so Microsoft says. I don't know if this applies to Vista/7 or is the same registry key, you'll have to Google it.

Just to follow-up, the feature Wipe Free Space Augeas mentions is part of another Piriform Product CCleaner

Thanks.