Microsoft Vista for such a large volume, is explained this way: we built for  our vista users millions of hardware drivers, and because the kernel upgrade, we must take into account compatibility with old kernel function, this has led to a volume of soared.
So for the next generation of Microsoft operating system: Windows 7, its volume be? Or not as bloated and Vista, right? Of course not, Microsoft's early in the development of a lot of lessons have been learned, a great improvement. A 2G memory laptop, installed Windows 7 Ultimate Edition, the space is probably the 9G, smaller than Vista full 3G! Our win fighters today will also share with you the next,the secret of Windows 7 further reduced "3G "fat. You are not curious about what is Win fighters it? Article finally, we will decrypt it!
1.Removal of virtual memory file to a non-system disk.


We all know that, in order to speed up the operation of the system. Windows provides a virtual memory mechanism, but in Windows 7, this feature is enabled by default, and the virtual memory file in the system disk. Such as a 2G memory machine, the virtual memory file size is 2G, we can remove it for the system disk space remaining.
The setting process:
The first step, right-click My Computer on the desktop, select Properties. You will see the system about interface, in the upper left corner of this window is the  Advanced System Settings.
Step Two: In the new pop settings window, select the first setting button. Into the performance settings, select the Advanced tab in the bottom of the Change button, enter the interface to set the virtual memory.
The third step: First, remove the check mark in the first box, so that we can modify the virtual memory size and location. Select the list of system disk partition, select the No paging file, click the set button next to, and then select the non-system partition, the following select System managed size, click the set button. If the middle of a dialog box appears, select OK on it.
2.Turn off the hibernation feature, save the memory size of disk space!
Please note that this dormancy function is not sleep.General laptop users may use that dormancy is all memory data is written to disk, and then shut down the system, start at the next boot, it will keep the data in the write back to memory, so hhe benefit is that you work in progress will be saved, even after power off is not back away, which is reason why people often say that do not shut down in a few months.
Most people do not often use this feature, and we paid for it was the same memory size of disk space. In fact, we can start it when needed, usually directly off it.
Dormancy function on and off specific ways:
Copy the code below, paste it into Notepad, then save the file as turnoffsleep.bat
@ powercfg -h off
Copy the code below, paste it into Notepad, then save the file as opensleep.bat
@ powercfg -h on

When we want to close and open the sleep function, simply use the administrator to run the above two bat file, very easy oh!
3.Compressed file, save 1G space!
In the Windows 7 folder, there is such a mysterious folder, its name is called winsxs, its volume is likely to be 3G. There's a lot of things, best not to casually delete. But we can also be squeezed out from it 1G space!

First we give the right-click menu to add a new menu option, "administrator ownership." Method is simple, install a software called Vista Manager can handle optimization. In the just mentioned winsxs folder right click and select our new '"The administator ownership." So that we can on this folder to edit their properties. in those crazy pop-up  CMD windows disappears, we again select properties of the folder in the righ-click, select the Advanced button on the bottom, the bottom of the Compress contents to save disk space , in front check mark the complex box.

Click OK to confirm all the way, the the process of compressing file began, during which there may be prompted to some files are in use, we directly choose to ignore all , may be continued for 20 minutes or so.

Above is the the details large weight of  Windows 7 system , we want to help.