Windows takes up >40GB of disk space

hard drivewindows 10

I have a serious problem with disk space on my laptop (a Medion Erazer), since the size of the Windows folder just keeps growing for no apparent reason.

Currently, it is at 41.9GB, which is three times as large as the Windows Folder on my desktop PC (I use Windows 10 pro on both). Is there a reason for this? And is there anything I can do about it?

I have identified the main space sinks as being the folders System32/DriverStore (17,8 GB), Software Distribution (6,8 GB), and WinSxS (4,4 GB), and of these only the WinSxS folder is anywhere near as big on my desktop PC.

I have already tried uninstalling old drivers from the driver store, which reduced the size of the DriverStore folder by 3GB, but it's still bigger than my entire Windows folder on my desktop PC.

What is causing this extreme bloat? And is there anything I can do about it?

Best Answer

Software Distribution folder

The Software Distribution folder is used by Windows Update for downloading updates before they are installed. From its size, it seems to contain an entire Windows version.

I suggest to check in Settings > Update & Security > Windows Update if you see "You're up to date". Even so, click on "Check for updates" to verify that nothing is pending.

If no updates are pending, you may clear it up, this way:

Start an elevated Command Prompt (cmd) and enter the commands:

    net stop wuauserv
    net stop bits
    rename C:\windows\SoftwareDistribution SoftwareDistribution.bak
    net start wuauserv
    net start bits

Reboot Windows and wait a day or two. If no harmful effects arrive, you may delete the backup folder SoftwareDistribution.bak.

DriverStore folder

This folder contains device driver packages that are ready to be installed. It also contains old versions of drivers that might be used to roll-back updated drivers.

It is best to let Windows manage this folder. But if it becomes too large, it can be cleaned up.

  • Create a restore point first before starting
  • Run the Disk Cleanup Wizard by pressing the Win+R and entering the command cleanmgr.exe
  • In the Disk Cleanup for (C:) window, click the Cleanup System Files button
  • Select the Device driver packages option
  • Click OK.

The above method will likely be insufficient to remove most of this folder. Removing more data will need to be done one driver after another with extreme caution.

You need first to make a list of all drivers using pnputil.exe /e > c:\drivers.txt. To delete all unnecessary drivers use the command pnputil.exe /d oemNN.inf, where oemNN.inf is found in the list.

Be very cautious when doing that, and boot for Windows to restore drivers wrongly deleted. Roll back to the saved System Restore point in case of an unrecoverable error.

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