Alex Ruben
How To Resolve Isdone.dll Error When Installing Large Games like Fitgirl and Dodi Repack (2025)
So, you’ve hit that annoying ISDone.dll error right when trying to install a huge game or a big repack? Yeah, it’s kinda frustrating, especially when you just want to play without fighting with errors. Often, it’s linked to corrupted or missing DLL files, bad RAM, or virtual memory settings that aren’t quite right. This guide aims to cover the common fixes that have worked on multiple setups — from missing DLLs to virtual memory hiccups — so you can hopefully get back to gaming without tearing your hair out. Just keep in mind, some things might take a bit of trial and error, and Windows can be pretty stubborn about some fixes.
How to Fix ISDone.dll Error During Game Installations
Download the Correct DLL Files and Essential Visual C++ Redistributables
This is a good starting point because, surprisingly, missing or corrupted DLLs like ISDone.dll or Unarc.dll often cause the error. Grab these files from trusted sources or, better yet, use official links. For example, download ISDone.dll and Unarc.dll. Also, get the latest Visual C++ Redistributable Runtimes All-in-One — this is kinda essential because outdated or missing runtime libraries often crash the install process.
Extract the DLL Files Properly
After downloading, don’t just toss these DLLs into random folders. Extract them using something like 7-Zip or WinRAR, and avoid running the DLL files directly from the downloads folder. Right-click the ZIP files, select Extract All, and choose somewhere easy — desktop is fine for now. Some folks swear by placing the DLLs directly into the Windows system folders, which is controversial but often works. Just be careful and always back up those folders first.
Move DLL Files Into the Right System Folders
Here’s where it gets kinda tedious, but not impossible. You need to copy those DLLs into the System32 folder for 32-bit apps and, if you’re on a 64-bit Windows (most are), into SysWOW64 also. The command line can help speed this up:
copy C:\Path\To\Extracted\ISDone.dll C:\Windows\System32\
copy C:\Path\To\Extracted\Unarc.dll C:\Windows\System32\And for 64-bit systems, do the same in C:\Windows\SysWOW64\. Sometimes, Windows throws a permission error; if so, run your command prompt as an administrator or do it via File Explorer with admin rights.
Funny thing — on some machines, this move has to be done twice or after multiple reboots. Windows can be weird about DLL caching or file permission… of course it has to make it harder than necessary.
Ensure Visual C++ Redistributables Are Installed Correctly
Running the install.bat file from the downloaded Redistributables folder as an administrator is a good move. Right-click, pick Run as administrator. A lot of times, the error pops up because some runtime components are missing or corrupted, which this installation should fix. After installing, a quick reboot helps ensure everything registers properly.
Set Your Virtual Memory (Paging File) Correctly
This is a hit-or-miss, but more often than not, virtual memory issues cause the installer to die with that error. In the past, jacking up your virtual memory or ensuring Windows manages it properly has straightened things out. To do this:
- Press Windows + R, type
sysdm.cpl, and hit Enter. - Under the Advanced tab, click on Settings in the Performance section.
- Once the Performance Options window pops up, go to the Advanced tab and click on Change under Virtual Memory.
- Uncheck Automatically manage paging file size for all drives.
- Select your C: drive, then choose Custom size. For a machine with 4GB RAM, use maybe 2048 MB for initial and 4096 MB for max — but adjust based on your setup.
- Hit Set and then OK. Time to restart and see if that fixes the error.
Yes, Windows likes to forget your VM settings sometimes, so don’t be surprised if it reverts after updates or restarts.
Finally, Restart and Check for Other Issues
After all this fuss, a full reboot is essential. Log out, shut down, and restart to let all those adjustments settle. Make sure your antivirus isn’t blocking any crucial files — sometimes, that’s why DLLs don’t register or get quarantined, causing errors.
Oh, and if you’re still getting errors, double-check your game files for corruption, or even try running the installer in compatibility mode or as administrator. Windows can be stubborn like that.
Extra: Tips for Common Pitfalls
- Make sure your Windows is fully updated — outdated OS can cause DLL conflicts.
- If you’re on a laptop, plug in your charger — virtual memory tweaks sometimes act funny on battery power.
- Run the installer with admin rights — right-click and pick Run as Administrator.
Summary
- Download necessary DLLs and Visual C++ runtimes.
- Extract and place DLL files into system folders carefully.
- Reinstall or repair Visual C++ runtime if needed.
- Adjust virtual memory settings, especially if you have limited RAM.
- Restart and check for lingering issues.
Wrap-up
Getting this error fixed is rarely one quick fix — sometimes it’s a combination of DLL updates, system tweaks, or RAM checks. But following the above steps has helped plenty of folks get past the block without reinstalling Windows or worse. Of course, troubleshooting can get messy, but hopefully this gives you a decent shot at resolving it yourself. Fingers crossed this helps.”