Ensure there are no special characters or Cyrillic/non-English letters in the installation path (e.g., use C:\Games\GameName instead of C:\Пользователи\Игры ). Summary Table of Fixes Why it works Re-download Data integrity Fixes corrupted setup files. Antivirus OFF Security conflict Prevents false-positive blocking. Admin/Safe Mode Access rights Bypasses permission issues. Virtual Memory System Resources Provides space for decompression. Chkdsk Disk Health Fixes bad sectors on HDD/SSD. Disable XMP Stops unstable RAM errors. Change Path Fixes illegal characters/paths. Still Not Working?
Press to select everything in this folder, and press Delete . Skip any files that Windows says are currently in use.
Download the DirectX End-User Runtime Web Installer from Microsoft. Run it. isdonedll error unarcdll error7 best
Search for sysdm.cpl -> Advanced Tab -> Performance Settings -> Advanced Tab -> Virtual Memory "Change" button.
Type msconfig in the Run box, go to the tab, check Safe boot , and restart. Run the game installer while in this mode. 5. Verify Archive Integrity (MD5 Check) Admin/Safe Mode Access rights Bypasses permission issues
If these methods fail, the issue might be with the repack itself, or your PC might be overheating during the process. Try to clean your PC fans or, if possible, move the setup files to a different computer to see if they work there. If you'd like, let me know: Which are you trying to install? Are you using a repack (like FitGirl) ? What is the target storage drive ? Share public link
Uncheck . Select your main Windows drive (C:) and choose Custom size . Disable XMP Stops unstable RAM errors
Next, type the command for the Unarc file and press Enter: regsvr32 unarc.dll
Select the drive where Windows is installed, choose , and set the Initial and Maximum sizes higher (e.g., if you have 8GB RAM, set both to 16,000MB) . Click Set , then OK , and restart your PC . 2. Run an SFC and DISM Scan
Click , press OK , and restart your computer to apply the allocations. 3. Disable Controlled Folder Access and Antivirus Engines
Windows Defender or third-party antivirus software frequently flags compressed repack scripts as false positives, deleting or locking isdone.dll or unarc.dll mid-install. Open via your Start menu. Go to Virus & threat protection > Manage settings . Toggle Real-time protection to Off .