WinRAR uses its own internal unarc.dll , while 7-Zip uses a different LZMA engine. One may be corrupted or version-mismatched.
The archive tool extracts the installer to a temporary folder (often with limited space or unusual permissions), and unarc.dll fails to map memory correctly.
| # | Action | Expected Result | |---|--------|------------------| | 1 | Run installer as Admin | 30% success | | 2 | Disable Antivirus + Windows Defender | 40% success | | 3 | Increase Pagefile to 24GB + restart | 70% success | | 4 | Fully extract archive (not run from inside) | 50% success | | 5 | Change install path to D:\Games\ | 20% success | | 6 | Re-download and verify file hashes | 60% success | | 7 | Reinstall VC++ Runtimes | 10% success | | 8 | Disable UAC temporarily | 15% success | how to fix unarc.dll returned an error code 14
Encountering the error message "unarc.dll returned an error code 14" is a frustrating experience, primarily because it halts installations—usually during the setup of large video games or software archives. You might be extracting a .rar or .zip file, running a setup.exe , or installing a game from a repack (like FitGirl or Razor1911), and suddenly the process stops with this cryptic error.
This error is almost never a sign of failing hardware or a virus. Instead, it points to a specific set of issues related to memory handling, file corruption, or Windows security settings. WinRAR uses its own internal unarc
| Cause | Description | |--------|-------------| | | The installer needs a contiguous block of memory (sometimes 2GB+). | | Corrupted downloaded file | A single bad bit in the archive can trigger code 14. | | Antivirus interference | Real-time scanning intercepts the DLL, causing memory allocation failure. | | Running installer from within an archive | Windows temp folder limitations cause space errors. | | Damaged unarc.dll | An old, missing, or overwritten DLL version. | | Path too long or contains special characters | Some installers fail with Unicode or long paths. |
unarc.dll requires write permissions to system temp folders. Without admin rights, memory allocation may fail. | # | Action | Expected Result |
Now, let’s fix it. This is the simplest fix, yet it works for 20% of users.