I just googled AutoCAD LT 2006 system requirements and found this blog post with the system requirements for AutoCAD 2006.
- Intel Pentium III or later with 800Mhz Processor
- Microsoft Windows XP (Professional, Home Edition, or Tablet PC Edition), Windows 2000
- 512 MB RAM (minimum)
- 500 MB free disk space
- 1024x768 VGA with true colour (minimum)
- Mouse or other pointing device
- CD-ROM drive
- Microsoft Internet Explorer 6 SP1
I didn’t realize it was originally for Windows XP, glad that it still works on Windows 10.
Unfortunately. I think @wilsontp is correct with the idea that AutoCAD 2006 works just fine on Windows 10 but the license manager doesn’t work correctly on Windows 10.
Microsoft builds fairly sophisticated backwards compatibly tools into the latest versions of Windows so that programs like AutoCAD 2006 still work.
However because license checking programs try to dig themselves into the OS to avoid any tampering by the user, it’s not always possible to come up with a way to make them work on newer versions of Windows.
Like if it uses a driver to directly work with the kernel in a way that is not possible in future versions of Windows as a new security feature will block it from working.
So in effect because the license checker is not entirely compatible with Windows 10 and AutoCAD requires it to provide proof that the license is valid then AutoCAD indirectly becomes incompatible with Windows 10.
AutoDesk might be aware that it’s just the license checker that doesn’t really work well on Windows 10 and it could be a relatively simple patch to make the program work but business wise it’s not worth the effort as it gains them nothing but requiring users buy a new version gains them more money.
From another point of view, it would just be nice to treat their customers well even if they don’t make money doing so but businesses don’t usually go for that unless they get good PR or reduced taxes by doing so.
However, there might be a way to workaround this problem, assuming AutoCAD will still let you reactivate the license again (if they decided to stop entirely then likely nothing can be done).
As mentioned by @wilsontp, you might be able to run AutoCAD on Windows XP inside of a Virtual Machine.
Virtual Machines are created via virtualization programs like Hyper-V and VirtualBox that emulate the hardware of a real computer to create a virtual machine you run on your real computer running Windows 10 that runs another OS like Windows XP where you can install a Windows XP program and use it in that virtual machine.
Because it’s a virtual machine running on your actual machine, things will work a little slower.
If you want to try this then you need a virtualization program installed and a CD with Windows XP on it along with a Windows XP license key to use in the virtual machine.
When Windows 7 Pro was released Microsoft actually provided a virtual machine they created with Windows XP already installed and ready to use to run older programs called “Windows XP Mode” which was easy to install and use.
Sadly, Microsoft didn’t keep this feature in Windows 8 and Windows 10 as it could still be useful to many people.