How can I reduce the size of Windows 7, and its CPU and memory usage?

My Windows 7 setup uses around 16GB while Windows XP only needs around 4GB hard disk space. Seems weird. I use Windows only for gaming so I don't need a lot of stuff they have to offer.

What is the best way to reduce the size of Windows 7? What can I delete / uninstall and how?

I'd also like to reduce the CPU and memory usage as much as possible (as long as it doesnt hurt game performance) - turning off all that fancy stuff and so on. What can I turn off and how?


4GB XP? 16GB Win7? That seems an awful lot. My vanilla win7 install on VirtualBox was around 5GB, and you can certainly get XP down to 700MB or so.

Use a visualisation tool such as WinDirStat to find out what's taking up all that disc.

Stuff to target, if you don't need it and you really know what you're doing:

  • unused Windows components (Control Panel -> Add/Remove -> Windows components, or in Vista+, All Control Panel -> Programs and Features -> Turn Windows features on or off)
  • System Restore
  • \Windows\System32\dllcache on XP
  • \Windows\System32\DriverStore\FileRepository on Vista+, if you're sure you're not going to need any more drivers out of it
  • \Windows\SoftwareDistribution\Download
  • %TEMP%, the IE cache, the trash
  • patch rollbacks (hidden $ folders in \Windows on XP)
  • example shared media and \Windows\Web
  • disable virtual memory to get rid of the pagefile (assuming you have enough memory to run swapless)
  • disable hibernation to get read of hiberfil
  • delete the large Chinese/Japanese/Korean fonts, if you don't use them
  • all vendor crapware (if an OEM install) must be destroyed as a matter of course

For some of these on Win7 you have to take ownership of the files back from SYSTEM before you can delete them.


You can turn off Aero by selecting one of the basic themes. This will reduce the load on your graphics card as Aero uses DirectX, which should improve performance while in Windows. It won't affect gaming performance as that uses full screen mode which bypasses Windows.

To reduce the disk space Windows takes up look at removing some components. On XP this was "Control Panel > Add/Remove Windows Components" - I don't have Windows 7 on this machine to double check if it's in the same place. As to what you could remove, I couldn't say. You'll know what you do and don't use.

Also, I've just checked in XP and there's not a lot you can remove and those items such as the games won't take up that much space.


Windows Vista/7 doesn't provide explicit way to disable hibernation. (I don't know why) You can make this with following steps :

  • Open command prompt with administrator privilege.
  • Type this : powercfg -h off

If c:\hiberfil.sys file disappear, it has worked.