Error isdone.dll means your computer does not have enough RAM or HDD memory → to make sure the computer has enough storage. 7

Error isdone.dll occurs when your computer is unable to read the installation archive files

This error is caused because your computer doesn’t have enough storage space (RAM / HDD) to keep the memory installation.

The standard error message cited isdone.dll is:

unarc.dll returned an error code -1

ERROR: archive data corrupted (decompression fails)

When you “install” a program (especially the larger ones),
Windows will decompress a series of “zipped” files.

To do this, Windows first opens the file in memory and then works on “extracting” it to your hard drive. For some computers, the compressed file’s size is too large, preventing it from decompressing properly.

If you want more information on this, look at the CAB files, which are at the core of most installations.

This error is most likely caused by insufficient RAM / hard drive space.


The fix is to make sure your computer has hardware running correctly and then make sure that the software (Windows / Antivirus) is not causing the problem:-

? Increase the Windows PAGE file size

The EASIEST solution is to increase the PAGE FILE size in Windows.

“Page File” is a file used by Windows to store data that cannot match RAM. Sometimes called ” virtual memory “and called a ” swap file ” in other operating systems, it’s a standard way to increase the size of all the memory your system can manage.

While using a single page/swap file extension is NOT recommended (slow at larger sizes), it may help with this situation:

To do this, you should follow these steps.

  • Press the ” Windows + R ” key on your keyboard
  • In the ” Run ” dialog box, enter ” sysdm.cpl ” and click ” OK
  • Click on the tab “ Advanced
  • Select the first ” Settings ” button in the Performance section
  • Click on the tab “ Advanced
  • Select the ” Change ” button in the Virtual Memory area :
  • Uncheck the checkmark in the box of ” Automatically manage …
  • Select ” Custom Size ” and then click ” Set
  • Then, click ” OK ” to exit the ” System Properties ” dialog box.

Doing this will increase the available memory size, which should allow you to install games on demand. You should restart your computer and try the installation again. This will allow you to install the game.

? Replace isDone.dll & unArc.dll

Although these two files are NOT the problem but replace them with:


Download it from

To do this, you should follow these steps:

  • Browse for the following URLs: isdone.dll & unarc.dll
  • On each page, click “ Download Now ” (Must Complete Verification)
  • Save each file (as a ZIP) to your hard drive.
  • Once the file is on the hard drive, double click to open it and then extract the DLL files from within:
  • Copy the newly extracted DLL and browse to C:/Windows/System32
  • Right-click and select ” Paste “
  • This may ask you to “Replace” the file – choose ” OK “
  • Then press the ” Windows + R ” key on your keyboard.
  • Type ” cmd ” into the ” Run ” dialog box and click ” OK “
  • In cmd, type the following:
 regsvr32 isdone.dll
regsvr32 unarc.dll

This will return a “success” message, which will help you install further.

1. Check memory

It is usually the case that a faulty module of RAM will cause the error.

The best way to determine if this is the case is to use either of these.
Windows Memory Diagnostic Tool, or a commercial tool called Memtest86 :

It would be best if you did the following (will require a reboot):

  • Press the ” Windows + R ” key on your keyboard
  • In the ” Run ” dialog box, type mdsched.exe and press ” OK “


Type ” mdsched.exe ” and click OK. Then, click “ Restart now and check for problems
  • This will cause Windows to restart and should load a screen like this:

Run the diagnostic test, and then it will reboot into Windows.

If there are any errors caused by this, you will need to remove the RAM. This can only be done by going to the system’s internal, which I explain in # 4.

2. ? RAM capacity

If the memory test (s) return to normal, you will need to make sure your RAM amount is not replaced. This can be done with Task Manager:

To access, use the following steps:

  • Press CTRL + ALT + DEL on your keyboard
  • In WINDOWS 7, this will automatically load the “Task Manager”
  • In WINDOWS 10, you will have to click on “Task Manager”:

In both cases, this will create the “Task Manager” interface, from which you should select the “Performance” tab at the top and then observe the system’s memory usage:

If the memory usage is anywhere near 100% (for example, 85%), you will have to stop any running apps:

This can be done by stopping their process in Task Manager or restarting in “Safe Mode”.

3. ? Stop processes (Reboot into Safe Mode)

If you find your memory to be okay, you will need to stop any processes from running. This will ensure that as much RAM is made available as possible.

The most effective way to do this is to reboot into Safe Mode. Safe Mode loads up to Windows without any additional apps, drivers, or services – allowing you to perform any maintenance requests. In our case, we will use it to free up the RAM on your system:

Safe Mode

The first step is to reboot into “Safe Mode”:

  • In Windows 7, click “Start” → “Restart”
  • Once you’ve rebooted, press F8 repeatedly on your keyboard before Windows starts to load
  • From here, use the F keys to select the option “Safe Mode” (usually F4):
  • In Windows 10, things are a little different.
  • It would be best if you had to press the “Windows” / “Start” button.
  • Then select the “Power” button from the menu on the left.
  • Hold SHIFT; then you need to select “Restart”:
  • This will load the “green” recovery environment (RE):
  • From here, select “Troubleshoot” → “Startup Settings” → “Restart”
  • This will reboot the system into the “Advanced Boot Options” screen:
  • Select “Safe Mode” and let the system load


Once you have Windows loaded into “Safe Mode”, you will want to stop any processes that the system may be running. You can do this with Task Manager :

4. ? Manually Change RAM (ONLY)

While seeing the error is enough for installation, playing the game is a pitcher of fish altogether.

If this is the case, you * may * want to replace the RAM manually. Of course, this is an advanced strategy recommended only for users with experience and understanding of the risks involved (you need to make sure that you don’t break any RAM):

5. ? Use “Swap File” (Page File in Windows)

Ultimately, perhaps the best way around this error is to use a swap file.

Swap files provide virtual memory for x86 / x64-enabled systems, allowing you to “add” RAM to your system while still using the same amount of RAM. It’s not recommended, but should work nonetheless:

  • Press “Windows” + “R” on the keyboard
  • Type “sysdm.cpl” and press “OK”:
  • Click the “Advanced” tab and then click the first “Settings” button:
  • This will load the “Virtual Memory” section, from which you should select “Advanced” and then “Change” (for the File Page):


This will set a new “Page” file size (will be used if your RAM capacity runs out).

As a side note, most people reading this kind of information online will only tell you “replace isdone.dll”. This is not correct.

This particular error has nothing to do with isdone.dll, unarc.dll, or any other DLL. It’s merely the case that your system doesn’t have enough RAM to continue reading the CAB file needed to install your game.