Quick answer: install.esd is the compressed file inside Windows installation media that holds Windows itself. It sits in the sources folder of a Windows 11 or 10 USB or ISO and usually contains several editions, such as Home and Pro. It’s a more tightly compressed version of install.wim. You can list its editions with dism /Get-WimInfo, convert one edition to WIM with dism /Export-Image, or use it directly as a repair source. A copy left in C:\ESD after an upgrade is safe to delete.
Applies to: Windows 11 and Windows 10 installation media, ISO files and the Media Creation Tool.
In this guide
What install.esd is
ESD stands for Electronic Software Download. When you open a Windows USB or ISO, you’ll find it at sources\install.esd. It’s usually between 3 and 5 GB and holds the complete Windows image that Setup copies to your drive.
One ESD file normally contains several Windows editions, each stored as a numbered index. Setup picks the right one based on your product key or the edition already installed. Microsoft’s Media Creation Tool typically builds USB drives and ISOs with install.esd, because the smaller file downloads faster and fits on a FAT32 USB drive.
install.esd vs install.wim
| install.esd | install.wim | |
|---|---|---|
| Compression | Higher (recovery compression) | Lower (usually LZX) |
| Typical size | About 3 to 5 GB | Often larger, and can exceed 4 GB |
| Fits a FAT32 USB stick | Usually yes | Not when over 4 GB, unless split |
| Mount and edit with DISM | No | Yes |
| Use as a DISM repair source | Yes, with the ESD: prefix | Yes, with the WIM: prefix |
Both contain the same Windows. The difference only matters if you want to customise an image, or if a tool asks specifically for a WIM file. Installation media you download or create may contain either one, depending on the version and the tool used.
See which editions it contains
Mount the ISO by double-clicking it (or plug in the USB) and note its drive letter, for example D:. Then open Terminal (Admin) or an administrator Command Prompt and run:
dism /Get-WimInfo /WimFile:D:\sources\install.esdDISM lists every image with its Index number and Name, such as Windows 11 Home or Windows 11 Pro. Index numbers differ between ISOs, so always check rather than guessing. To see details for one edition, including its version and language, add /Index:6 with the number you want.
Convert install.esd to install.wim
DISM can’t mount or edit an ESD file, so convert the edition you need into a WIM first. This exports one index at a time:
dism /Export-Image /SourceImageFile:D:\sources\install.esd /SourceIndex:6 /DestinationImageFile:C:\Images\install.wim /Compress:max /CheckIntegrity- Create the destination folder first (here
C:\Images) and make sure it has several GB of free space. - Replace 6 with the index from
/Get-WimInfo. - Run the command again with another
/SourceIndexand the same destination file to add more editions to the WIM. - Exporting takes several minutes, because the high ESD compression has to be unpacked.
If the resulting WIM is over 4 GB and you need it on a FAT32 USB drive, split it into parts that Setup can read:
dism /Split-Image /ImageFile:C:\Images\install.wim /SWMFile:C:\Images\install.swm /FileSize:3800Copy the .swm files to the USB drive’s sources folder in place of install.wim. For most people, though, it’s simpler to let a tool build the USB for you: see how to create Windows installation media or how to make a bootable USB with Rufus.
Use install.esd to repair Windows
When DISM /RestoreHealth fails because it can’t download repair files, it can use the ESD on matching installation media instead. Use an ISO of the same Windows version, edition and language as the PC, and the index of your edition:
DISM /Online /Cleanup-Image /RestoreHealth /Source:ESD:D:\sources\install.esd:6 /LimitAccessThe ESD: prefix and the :6 index at the end are both needed. /LimitAccess stops DISM trying Windows Update first. After it completes, run sfc /scannow. If DISM reports that the source files couldn’t be found, see error 0x800f081f, which usually means the ISO doesn’t match the installed build. To repair a PC that won’t start, see how to run SFC offline.
Can you delete install.esd?
- In C:\ESD or C:\$WINDOWS.~BT: these are left over from an upgrade or the Media Creation Tool. Once Windows has finished upgrading and you don’t need to roll back, they’re safe to remove. The cleanest way is Disk Cleanup: run
cleanmgr, select Clean up system files and tick Temporary Windows installation files. - On a USB installer or ISO: don’t delete it. Without it the media can’t install or repair Windows.
- In C:\Windows: a running Windows installation doesn’t keep an
install.esdthere. If you find one somewhere unusual, check what created it before removing it.
Related guides
- Windows 10 installation media: create a USB or ISO (step by step)
- Error 0x800f081f: how to fix it in Windows 11 and 10
- How to run SFC offline from the recovery environment
- Windows cannot find the Microsoft Software License Terms: how to fix it
Official sources: for more detail, see Microsoft’s own pages:
Frequently asked questions
Can I open install.esd like a ZIP file?
Not with File Explorer. Recent versions of 7-Zip can open many ESD files and extract individual files, but for anything that touches the Windows image itself, DISM is the reliable tool.
Why is my install.esd smaller than install.wim?
ESD files use stronger compression. The Windows inside is the same; it just takes longer to unpack.
Can I install Windows directly from install.esd?
Yes. Windows Setup reads ESD files directly, so a USB drive with sources\install.esd installs normally. You only need a WIM if you plan to customise the image.
Which index is Windows Pro?
It depends on the ISO. Run dism /Get-WimInfo and read the names; on many consumer ISOs Pro is index 6, but don’t rely on that.
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