For years I used AutoCAD LT 98, its not 3D but I only need 2D anyway. I learned CAD on AutoCAD Release 9 and have used other Autodesk products. Fast forward now to a computer with Windows 7 Pro 64 bit. Can't even load LT 98 let alone run so I am using Draftsight 64 bit a very nice program.
But it seems you need to re-new your registration every year and put up with the almost daily marketing emails.
Draftsight works fine and it even reads AutoCAD files from 1992. It is so much like the real product there is no learning curve. You can buy the Pro version for $200 - $300 but it needs to have a yearly subscription paid of $99.
So I am thinking of purchasing a legal new and unused, forever copy of AutoCAD 2007 or 2008. Dan uses DoubleCAD and I am thinking of downloading and trying. Open to suggestions about AutoCAD LT and how it works on Win 7.