If you use VBA inside of 32bit AutoCAD you will have noticed that it is around 1000x times slower when running the same VBA code inside of 64bit AutoCAD.
This is because AutoCAD 64bit ships with the 32bit VBA DLL in a separate out-of-process executable rather than loading the VBA DLL inside of AutoCAD itself. Therefore, a lot of marshaling is incurred communicating between the out-of-process VBA executable and 64bit AutoCAD.
Other issues you may be seeing: Run-time error ‘429’: ActiveX component can’t create object
The best solution is to install 32bit AutoCAD on 64bit Windows, here are the affected versions along with their solution text…
Using Windows Explorer, copy Disk 1 of your AutoCAD 2008 CD to your hard drive, to a folder path c:\Autodesk\AutoCAD2008
If you have more CD’s, copy them all directly over the top of Disk 1, overwrite all files in your previously copied c:\Autodesk\AutoCAD2008 folder
If you have a single self extracting exe downloaded from Autodesk
Run the exe, it will ask to unzip to a folder inside of c:\Autodesk, make a note of the folder for later use (we’ll refer to it from here as c:\Autodesk\AutoCAD2008), now click OK. Wait until all of the files have extracted, when they do, the AutoCAD 2008 setup will automatically launch – simply close it and move to the next step.
Now, start the Longbow Converter tool, select the 1st tab, pick the c:\Autodesk\AutoCAD2008folder, and click the Convert button.
Once the conversion process is complete, click Install/Run Setup to start setup. Simply install as normal.
Windows 8, Windows 8.1 and Windows 10 users: Once the installation process is complete, go back to the Converter, select the 3rd tab, pick the newly installed C:\Program Files (x86)\AutoCAD 2008 folder, then click ‘Fix’
Now you can happily run your AutoCAD 2008 32bit on Windows 7, Windows 8, Windows 8.1 and Windows 10
If you are getting Error 1935. An error occurred during the installation of assembly ‘Microsoft.VC80.OpenMP.type=”win32″.version=”8.0.50727.42″ when installing your AutoCAD 2008, try these steps to resolve it:
Delete all files (*.*) from your C:\Windows\System32\config\TxR folder