discussion Guide Windows ISDone.dll Error in Windows – Causes and Fixes

[Kreathex]

The “ISDone.dll” error is a common issue for Windows users, especially during game or large software installations.
It usually appears as:

• “ISDone.dll error occurred”
• “Unarc.dll returned error code -7”
• “ISDone.dll not found or could not be loaded”

This error occurs when the system encounters memory or disk integrity problems while extracting large archive files (setup.bin, data.cab, etc.).
Summary:
ISDone.dll is a file Windows uses to manage game installations; if it’s missing or corrupted, the installation fails.

When ISDone.dll Errors Occur​

• During game installations, especially compressed repacks
• Together with Unarc.dll errors
• Running ISO or setup.exe files
• After Windows updates
• When RAM or disk space is insufficient

Causes of ISDone.dll Errors​

Cause	Explanation
Missing or corrupted DLL	ISDone.dll or Unarc.dll deleted or damaged
Insufficient RAM or virtual memory	Memory fills up during installation
Corrupted setup archive	Downloaded game files are faulty
Antivirus interference	Security software blocks setup files
Windows system file error	DLL registration corrupted
Incompatible installer	Older installer conflicts with new system

How to Fix ISDone.dll (Step-by-Step)​

Follow these methods in order:
1. Restart as Administrator

• Right-click the setup file → Run as Administrator
  Some installers need system folder write access; admin rights may solve the problem.

2. Temporarily Disable Antivirus / Windows Defender

• Antivirus may flag setup.bin or DLL files as suspicious.
• Taskbar → Right-click antivirus → Pause protection
• After installation, re-enable it.
• Alternatively, add the setup folder to the safe list.

3. Increase Virtual Memory
Insufficient memory is a common cause.

• Control Panel → System → Advanced System Settings
• Performance → Settings → Advanced → Virtual Memory → Custom Size
• Initial size: 4096 MB, Maximum: 8192 MB (4–8 GB)
• Save and restart

4. Repair System Files (Command Prompt)

• Start → type cmd → Right-click → Run as Administrator
• Run commands:

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

• Restart after completion

5. Manually Re-register ISDone.dll

• Place ISDone.dll in C:\Windows\System32
• Use only official Microsoft or trusted sources
• Open Command Prompt and run:

regsvr32 isdone.dll

6. Redownload Setup Files

• Corrupt or incomplete setup/ISO may cause the error
• Download a fresh copy from a trusted source

7. Check Disk for Errors

• File Explorer → C: → Right-click → Properties → Tools → Check

8. Install Game to a Different Directory

• Avoid long paths or Turkish characters; use something like C:\Games
  

ISDone.dll Error Table​

Cause	Fix
Missing/corrupt DLL	Re-register ISDone.dll
Insufficient RAM/virtual memory	Increase virtual memory (4–8 GB)
Corrupt setup/ISO	Download fresh files
Antivirus interference	Temporarily disable antivirus
Disk errors	Run disk check (chkdsk)
System file corruption	Run sfc /scannow

Additional Tips:

• Extract setup files to a fixed drive, not Desktop
• Close background apps during installation
• Keep archive programs (WinRAR, 7-Zip) updated
• If “Unarc.dll returned an error” appears, re-register both DLLs