Question on defragging and disk space

[frozentundra123456]

I recently defragged my hard drive using Smart Defrag. Before defragging, the computer said I had 315Gb of free space. After defragging it went down to 275Gb. This was immediately after defragging, no added programs or use of the computer at all. I have noticed the same thing when defragging with the built in Vista defragger.

If I do disk clean up, the "free space" magically somehow reappears.

Can someone explain what is happening? Also, if I run disk clean up immediately after defragging, does this eliminate the benefits of the defrag?

My system is Acer off the shelf, 500 gb hard drive, Vista 32bit, E4500 and 9800GT. I used the deep defrag and optimise option in smart defrag because some folders were opening slowly. Probably wont help, but cant hurt can it??

 

[FishAk]

I can't answer your question, but I suggest you give "Auslogics Disk Defrag" a try. It's free, very fast, and quite good.

 

[Blain]

Think of it like this...
You go around your house and put all your trash in a trash can.
Your house is now clean, but if you don't take the trash outside, the trash is still physically taking up space in your house.

That's kind of rough analogy, but you get the idea.

 

[Nothinman]

Vista and up automatically defrag during idle time, you're just wasting time thinking about it.

 

[Zargon]

Vista and up automatically defrag during idle time, you're just wasting time thinking about it.

this.