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Home » How to Fix isdone.dll/unarc.dll Error on Windows 11/10/8 – 10 Ways to Fix it!

How to Fix isdone.dll/unarc.dll Error on Windows 11/10/8 – 10 Ways to Fix it!

At the time of unpacking or installing a large size of game on your computer, the isdone.dll/unarc.dll error may appear. If you are unable to install your favorite game on Windows 11/10/8 computer, try to apply the fixes, mentioned in this article.

Error Message:

An error occurred when unpacking!
unarc.dll returned an error code: -1
ERROR: archive data corrupted (decompression fails)

The unarc.dll is associated with isdone.dll.

How to Fix the isdone.dll/unarc.dll error?

When you unpack a large compressed file, it consumes SSD and RAM space. If it found a lack of SSD/RAM space, it returns the above error.

In this article, there are some useful methods are described that will resolve isdone.dll/unarc.dll related error.

Method 1: Fix using the Outbyte PC Repair Tool

If there are bugs in the computer like missing other dependency dll files, corrupted system files, outdated drivers, bugs in registry files, malware running, etc, then you are likely to get several kinds of errors including the isdone.dll/unarc.dll error.

Use Outbyte PC Repair Tool to scan and fix all the computer errors and optimize your PC for better performance.

Windows is made with huge number of dll files, exe files, sys files, various types of services, databases, etc so, it is not possible to keep monitoring all the files always. A brilliant PC Optimizer tool repairs damages, fix errors, update windows and drivers, and eliminate various types of errors silently.

Outbyte PC Repair Tool does all the above task easily and provides you an errorfree and smooth Windows environment to work so that you can focus on your business only.

3 Steps to Fix this Error
Step 1. Download Outbyte PC Repair Tool [File Size: 16.4 MB]
Step 2. SCAN your Windows PC
Step 3. Click Fix button to Repair Error

Method 3: Clean-up System Memory

The first step you should take is to clean the memory and arrange some extra space in SSD.

Step 1: Delete unused large files.
Step 2: Run the Disk cleanup utility. Click on the Start menu and Search for Disk clean-up and open it.
Step 3: Select Drive Letter (C:) and click OK.


Step 4: Click on the Cleanup system files button.


Step 5: Again, select Drive Letter (C:) and click OK.


Step 6: Select all the files and click OK.


Method 4: Upgrade the bigger Size of SSD and RAM

It is the best idea to increase the size of the SSD and RAM. The isdone.dll/unarc.dll error occurs due to the lack of spaces so, replacing the hardware with a bigger size can fix this problem easily.

Method 5: Run System File Checker Tool.

System File Checker tool checks the integrity violation of system files and if it founds any corruption, it repairs or replaces them. It is a very useful command line tool that fixes corrupted system files issue quickly.

Step 1: Open Elevated Command Prompt.

open command prompt as administrator in Windows 8, 10 & 11

Step 2: Run the below command.
sfc /scannow
Step 3: Wait to finish the process.

Method 6: Run the CHKDSK command to repair the disk error.

Step 1: Open Elevated Command Prompt.

open command prompt as administrator in Windows 8, 10 & 11

chkdsk /f c:

Method 7: Optimize the installation drive.

There might be problems in the installation drive, so you are getting the isdone.dll/unarc.dll error. You need to optimize the installation drive before unpacking the files.

Step 1: Open This PC. Right-click on the C drive and select Properties.

Step 2: Go to the Tools tab and click Optimise button.


Step 3: Select the drive and click on the Optimise button to start optimization.


Method 8: Run a Malware/Virus scanner.

If there is malware or viruses are running in the background, it may consume huge system memory and force the PC to throw an isdone.dll/unarc.dll error when unpacking a larger file. Scan your PC with trusted antivirus software and remove all the viruses and malware from your computer.

Method 9: Re-register the isdone.dll/unarc.dll file.

Re-registering the isdone.dll/unarc.dll file may fix this error sometimes.

1. Open the command prompt as administrator.
2. Run the following commands.

regsvr32 Isdone.dll
regsvr32 unarc.dll

3. Reboot the PC.

Method 10: Increase the virtual memory size.

If you have large HDD/SSD space but insufficient RAM, you can add some virtual memory to RAM.

Step 1: Go to Settings ➜ System ➜ About.
Step 2: Click on Advanced System Settings link.


Step 3: Go to the Advanced Tab and click Settings under the Performance section.


Step 4: Go to the Advanced tab and click on the Change button to increase the virtual memory size.


Step 5: Uncheck "Automatically manage paging file size for all drives". Select Custom size and insert 16 for the Initial size and 2048 for the maximum size.


Step 6: Click Ok to save.


If you are getting the isdone.dll/unarc.dll error when unpacking a large size of compressed files, increase the memory size of your HDD/SSD and RAM. Apart from it apply the solutions given in this article to fix it.