Installing AutoCAD LT97 on Windows 11

AutoCAD LT97 users are very used to the software package and cannot do without it. With the latest hardware and required move to new Windows versions, trying to install your AutoCAD LT97 gives an error like this one…
Windows 16bit setup error - This app can't run on your PC

“This app can’t run on your PC”

or this one…
Setup Halted System requirements error Wrong OS, AutoCAD supports Windows NT 4.0, Windows NT 5.0, Windows 95 and Windows 98
“Wrong OS, AutoCAD supports Windows NT 4.0, Windows NT 5.0, Windows 95 and Windows 98” …all is not lost, follow these instructions to install your AutoCAD LT97 on Windows 11…

Ransomware Protection Windows 11 and AutoCAD

Just before we start note that Windows 11 comes with a Ransomware Protection which includes Controlled Folder Access. Controlled folder access blocks applications from writing to your Documents, Pictures, Videos, Music, Public and Favorites folders. AutoCAD versions all the way to AutoCAD 2021 write to certain user Public folders and are therefore blocked by this feature. This can cause issues with all sorts of things including activating your AutoCAD license and even running AutoCAD. Ransomware Protection is an important feature of Windows 11 but it will affect your AutoCAD unless you allow AutoCAD and its dependent applications access to the controlled folders.

How to install AutoCAD LT97

A quick word of advice: please follow the instructions below precisely as documented including using the same folder names and paths. This will significantly reduce the risk of having any


  1. If you don’t yet have a copy of the Longbow Converter App you can purchase it here or click on the download link we sent you via email in order to download the Converter App to your PC.
  2. Before installing the Converter App, make sure the files downloaded from our site are not blocked by Windows SmartScreen… Windows 11 is finicky, click the TLC zip first to make sure it’s fully selected then Right+click the file and select Properties. Be sure to check the Unblock checkbox as shown below and Click OK…
  1. Double click the zip file to open it and install the TLC application as normal. By the way, TLC stands for The Longbow Converter
  2. Once installed, start the Longbow Converter App…
    1. Now place your AutoCAD LT97 CD in the CDRom Drive
    2. In the Converter App, select the 2nd tab named “Old AutoCAD Installer Reviver
    3. Using the “. . .” button, select your AutoCAD LT97 installation CD
    4. Next, click the “Run Old Installer” button and follow the onscreen instructions. If all is well a dialog will appear stating success, simply click OK to start your AutoCAD setup
      1. Now I know it’s unheard of these days, but at this point expect to wait up to 45 minutes for your AutoCAD LT97 setup.exe program to appear, be patient – NOTE: do not continue with the install until reading the next step…
    5. Once the setup starts, stop and read the next steps all the way to the end! By the way, if your AutoCAD LT97 setup does not start after 45 minutes, read the Troubleshooting section below.
  3. In the AutoCAD setup program…
    1. navigate through each setup dialog as normal, with these exceptions…
      1. Make sure you do a Typical Install (not a Full Install)
      2. When you get to the installation folder input dialog **it’s vitally important to make sure you install to c:\acadlt97 (not Program Files\AutoCADLT97 as usually prompted)**
  1. Now carry on with the install
    1. Do not reboot once the install is complete
    2. Ignore any errors related to not being able to create the shortcut e.g. “Cannot Create folder ‘AutoCAD LT97’, you will have to create a shortcut on your computer Desktop to your c:\acadlt97\aclt.exe by hand.
    3. Again, do not reboot if prompted to do so
  2. Once your AutoCAD setup has completed the installation…
    1. Make sure you fully close the setup program.
    2. Once the setup is closed the Converter will automatically fix the c:\acadlt97 program files. You should see “Success!” displayed in the 3rd tab named “Old AutoCAD Program Reviver
    3. Now reboot your PC
  3. You can now run your AutoCAD LT97, using Windows Explorer, navigate to c:\acadlt97 and double click aclt.exe


  • If your AutoCAD LT97 setup is not starting after 45 minutes…
    1. First try turning off UAC, rebooting, then restart the steps above.
    2. If it is still failing, most likely it’s because of another application on your system which is preventing our setup routine from starting (perhaps anti-virus, or similar) – try installing LT97 from Windows Safe Mode
  • If you are getting an application failure with Unhandled Exception 0x800F0922
    • The security software (ESET Nod 32) must uninstalled; suspending it not effective
  • If you are getting a WinHelp() error when pressing F1 to try and access the Help system then simply install the WinHelp (WinHlp32.exe) module from Microsoft
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