WinSxs Folder consuming enormous disk space

Reply to this one, Brian engineer.

WinSxS Folder

The WinSxs is the central file repository for Windows. All files installed are placed into the WinSxS folder including updated files. So you'll have lots of different versions of each file allowing you to roll back Windows updates and service packs to any previous state.

The current version of a file is hardlinked to the appropiate place in the rest of the file system. A hardlink is a file name. All files have at least one hardlink. Windows system files have two hard links, one in WinSxS and one in (usually) c:\windows\system32. Both names point to the same bytes on disk.

As the files have two names they are counted twice by explorer, once in System32 and once in WinSxS.

There are other uses for it as well. It allows multiple programs to use different versions of dlls.

Ensure Pending Operations are Completed

Try a reboot. Before rebooting set the trustedInstaller service (DisplayName Windows Modules Installer) startup to automatic. Normally it's manual unless an operation such as windows update requires boot time install.

Click Start - All Programs - Accessories - Right click Command Promptand choose Run As Administrator. Type (or copy the below line and one blank line underneath and right click in the command prompt window and choose Paste).

sc config trustedinstaller start= auto

Then Reboot

System Update Readiness Tool

Ensures the consistancy of the WinSxS (Side by Side) folder. 

http://windows.microsoft.com/en-AU/windows7/What-is-the-System-Update-Readiness-Tool

For 32 bit Windows

http://www.microsoft.com/en-us/download/details.aspx?id=504

For 64 bit Windows

http://www.microsoft.com/en-us/download/details.aspx?id=1540

To see results click Start - All Programs - Accessories - Right click Command Prompt and choose Run As Administrator. Type (or copy the below line and one blank line underneath and right click in the command prompt window and choose Paste).

notepad %SYSTEMROOT%\Logs\CBS\CheckSUR.log

Afterwards delete this folder to reclaim 100 MB.

del "C:\Windows\CheckSur" /s

Start the Scavenger

Adding or removing a Windows feature from Control Panel - Programs and Features initiates a scavenging operation on Vista.

Sizes Are Not What They Seem

Files in WinSxS are usually hardlinked files. A hard link is a filename. Every file has at least one hard link. Files in system32 and files in WinSxS are usually hardlinks to the same file. Therefore you count the same file in system32 and WinSxS twice.

Remove files updated by Service Packs

To see how much space it taking up type what's below and note the total size (because it will scroll away). Also note that the total is higher than it actually is. This will remove the ability to uninstall the service packs.

Start - All Programs - Accessories - Right click Command Prompt and choose Run As Administrator. Type (or copy and paste by right clicking in the Command Prompt window and choosing Paste).

dir c:\Windows\WinSxS /a /s

Then type

VSP1CLN.exe

COMPCLN.exe

Then to see the new size and compare to the old size

dir c:\windows\WinSxS /a /s

I`m using Vista Home SP2 !

What is cmd or .exe to be used on SP2 ???

Thanks !

Morais