Error 0x8007025D: how to fix it when installing or upgrading Windows

Applies to: “Windows cannot install required files. Error code: 0x8007025D”, “0x8007025D – 0x2000C” upgrade failures, and the same code in System Restore or Windows Update, on Windows 11 and Windows 10.

What error 0x8007025D means

The code wraps Windows system error 605, ERROR_BAD_COMPRESSION_BUFFER, which Microsoft describes as “The specified buffer contains ill-formed data.” In plain terms, Windows tried to decompress a file (Windows setup files are stored compressed inside install.wim or install.esd) and the data it read didn’t make sense.

That points to one of four places where data gets damaged:

• The source: a corrupted ISO download, a faulty or counterfeit USB flash drive, or a scratched DVD.
• The connection: a loose USB port, hub or extension cable that drops data.
• The PC’s memory: faulty RAM can corrupt data as it’s unpacked, even when the USB is fine.
• The target drive: bad sectors where setup is writing its files.

If you see 0x8007025D – 0x2000C during an upgrade, the second part means it failed in the SAFE_OS phase while applying the image. The causes and fixes are the same.

Quick checks first

• Unplug every USB device you don’t need: printers, card readers, external drives and hubs. Keep only the keyboard, mouse and the installation USB.
• Plug the installation USB directly into the PC, ideally a rear port on a desktop, not a front panel or hub.
• Make sure the target drive has plenty of free space. Windows 11 needs a drive of at least 64 GB, and an in-place upgrade needs tens of gigabytes free.
• If you overclocked the CPU or memory, or enabled an XMP/EXPO memory profile, reset BIOS settings to defaults for the install. Unstable memory settings can produce exactly this kind of error.
• When upgrading from inside Windows, temporarily turn off third-party antivirus. It can lock setup files while they’re being extracted.

Fix 1: Recreate the installation USB

This fixes most cases, because the error usually comes from the media. Don’t just copy the same ISO again: get a fresh copy.

1. On a working PC, download Microsoft’s media creation tool from the official Windows 11 download page (or the Windows 10 page for Windows 10).
2. Use a different USB flash drive of at least 8 GB if you can. Cheap or old drives are a common cause.
3. Run the tool, choose USB flash drive and let it download and write the files.
4. Boot the PC from the new USB and run setup again.

If you prefer an ISO with Rufus or another tool, download a fresh ISO from Microsoft rather than reusing an old one. For step-by-step help, see how to create Windows 10 installation media.

Fix 2: Clear old setup files and retry the upgrade

If the error appears while upgrading from inside Windows (through Windows Update, the Installation Assistant or setup.exe), the downloaded files in C:\$WINDOWS.~BT may be damaged. Clear them so setup downloads fresh copies:

1. Press Win + R, type cleanmgr and press Enter. Choose the C: drive.
2. Select Clean up system files and pick the C: drive again.
3. Tick Temporary Windows installation files (and Windows Update Cleanup if listed), then select OK and Delete Files.
4. Restart the PC and run the upgrade again.

If it still fails when upgrading in place, a clean install from a freshly made USB (Fix 1) usually gets past it. Back up your files first; see how to reinstall Windows 10.

Fix 3: Test the PC’s memory

If a brand-new USB gives the same error, test the RAM. Windows includes a basic memory tester:

1. Save your work, then search for Windows Memory Diagnostic in Start and open it (or run mdsched.exe).
2. Select Restart now and check for problems (recommended).
3. The PC restarts and runs the test, which can take a while. When Windows starts again, the result shows as a notification, or in Event Viewer under Windows Logs > System from the source MemoryDiagnostics-Results.

If it reports errors, or you just want to be sure, test with one memory stick installed at a time, or swap the slots, and run setup with only a known-good stick. A longer test with a dedicated tool such as MemTest86 catches faults this quick test can miss.

Fix 4: Check the target drive for errors

When upgrading from Windows, check the system drive first. Open Terminal (Admin) (Windows PowerShell (Admin) on Windows 10) and run:

chkdsk C: /scan

If it reports problems, run chkdsk C: /f, type Y to schedule it, and restart. For a clean install, you can delete and recreate the partitions in setup’s Where do you want to install Windows? screen, which also clears any damaged file system. That erases the drive, so only do it after backing up.

Fix 5: Repair Windows with SFC and DISM

When the error appears inside a working Windows (in Windows Update, a feature update or an app install), repair the system files. In Terminal (Admin), run these one at a time:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

Restart after both finish and try again. If DISM itself fails, see error 0x800f081f, which covers DISM source errors.

If you see 0x8007025D in System Restore

System Restore can show the same code when it can’t read or write a file it needs. Run it from the recovery environment, where fewer files are in use:

1. Open Settings > System > Recovery and select Restart now next to Advanced startup. (Windows 10: Settings > Update & Security > Recovery.)
2. Choose Troubleshoot > Advanced options > System Restore and pick the restore point.
3. If it still fails, turn off third-party antivirus in normal Windows, run sfc /scannow and chkdsk C: /scan as above, and try another restore point.

Still failing? Read the setup log

Windows setup records the exact file it couldn’t extract. After a failed upgrade, open C:\$WINDOWS.~BT\Sources\Panther\setuperr.log in Notepad and search for 0x8007025D. A line such as Cannot extract file ... from ... install.esd confirms the setup files themselves are damaged, which points back to Fixes 1 and 2. If the same file fails every time from fresh media, suspect RAM or the drive.

Related guides

• Windows 10 installation media: create a USB or ISO
• How to reinstall Windows 10
• Error 0xC1900101 – 0x20017: how to fix it
• Error 0x800f081f: how to fix it
• We couldn’t update the system reserved partition: how to fix it

Official sources: for more detail, see these pages:

• Microsoft Learn: System error codes 500-999 (ERROR_BAD_COMPRESSION_BUFFER)
• Microsoft: Download Windows 11 and the media creation tool
• Microsoft Support: Use the System File Checker tool

Frequently asked questions

Is error 0x8007025D a hardware problem?

Often it’s the USB drive or download, which is cheap to fix. If fresh media on a different flash drive still fails, the PC’s RAM or drive becomes the likely cause.

Can a USB 3.0 port cause 0x8007025D?

A loose or unreliable port can. Try a different port, preferably on the back of a desktop, and avoid hubs and extension cables during setup.

Why do I get 0x8007025D in a virtual machine?

The same causes apply: a damaged ISO file or a problem with the host’s memory or disk. Re-download the ISO from Microsoft and check the host PC.

Will I lose my files fixing this error?

Recreating the USB, cleaning setup files, testing RAM and running SFC don’t touch your files. Only a clean install that deletes partitions erases data, so back up before that step.