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Officially, AutoCAD 2004 and 2005 is not compatible with Windows Vista or Windows 7.
Even AutoCAD 2007 required a service pack in order to run on Windows Vista.
The link here from AutoCAD gives the versions that are compatible on Windows Vista.
If you do get it running it may be unstable. You can try to run in Compatibility mode of Windows XP operating system.
If you are Windows 7 Professional, Ultimate or Enterprise, you may try Windows XP mode and Virtual PC.
Running Windows XP Mode requires:
1. Windows 7 Professional, Enterprise, or Ultimate editions.
2. A computer capable of hardware virtualization. This means your computer has a central processing unit (CPU) with either Intel-VT or AMD-V virtualization features.
3. Virtualization features turned on in your computer’s basic input/output system (BIOS).
To determine whether your computer’s CPU is capable of hardware virtualization, go to the Windows XP Mode and Windows Virtual PC support website and download a utility that can check whether your Intel or AMD CPU is compatible.
To find your brand of processor so you can download the appropriate utility, click the Start button , right-click Computer, and then click Properties. Under System, next to Processor, you can see what type of CPU you have.
Even if your CPU can run Windows XP Mode, you might also need to turn on virtualization settings in your computer’s BIOS. Procedures vary depending on the BIOS manufacturer. For more information, see BIOS: frequently asked questions.
