BleepingComputer.com: Three questions!

Questions:


1. My (C:\) drive tells me that I only have 75.7 Gb of free space (out of 222 Gb), but when I added up the folders inside, it takes about 1858.398 Mb of space. What happened to my seemingly unused 220.141602 Gb? I don't have too many applications installed on my computer to take up that much space.


2. Is it completely safe to delete absolutely everything inside <C:\Users\Username\AppData\Local\Temp>? Will deleting its contents affect my computer in any way?


3. I know that deleting and emptying the trashcan doesn't "permanently erase" the files, as the trashcan says it does, but instead places the deleted files somewhere hidden(?). How can I make sure the files that I delete are permanently deleted without leaving a trace (without taking extreme measures, of course)? I would want to avoid formatting the computer in any way, since there still are files that I need on the computer.










Thank you so much in advance for taking the time to view these questions!
Any kind of help regarding these questions will be greatly appreciated!

1. Most likely it's in "hidden" folders like System Volume Information, and with the pagefile and hibernation file.
To find out for sure, use this free tool: http://w3.win.tue.nl/nl/onderzoek/onderzoe...n/sequoiaview//

2. It should be safe to delete it, but I'd suggest using a Temporary file cleaner (such as the Disk Cleanup Tools in the Accessories...System Tools startup menu).

3. It depends on how secure you want to be. Deleted files are fairly easy to find, but you can use different freeware applications to ensure that they're completely deleted. Here's a link to our Freeware page(s): http://www.bleepingcomputer.com/forums/topic3616.html