AutoCAD drawings cant be open! Help!?

Question

I spent like a month to finish a project on my laptop and now i cant open them!! omg help me!! I was using AutoCAD 2006 to finish them, n then i accidentally deleted the program(not the files though), and then i installed AutoCAD LT 2005, and all the files cant be open. It says "File is not valid".
Whats wrong with it?? HELP!
I need to submit them by the 30th this month.. helpppp T_T

Answer 1

Sounds like AutoCAD 2006 created some features in the file that can't be recognized by an older version of the software. Do you have access to another installation of AutoCAD 2006 or newer? I would guess that your school probably has this.

Is your file in DXF or DWG format (sorry, I'm only partially familiar with AutoCAD as it relates to mapping projects so I've only worked with these file types from AutoCAD)? You might find some utilities that can convert the file between several formats and get it back into a format that you can use with the older AutoCAD format. You could even find that if the file is corrupted in some way that the conversion utility will gracefully handle the error and at least restore most of the file to you.

Oh, hopefully you have learned a valuable lesson too that you should always save multiple copies of any important assignments in multiple locations (different systems is possible but definitely not on a single hard disk). I've had enough friends lose their important files in the past to know that a good backup and versioning strategy saves a lot of headaches.

Answer 2

That is because you are trying to open a 2006 file in an older version. try to open the file in a version above 2005 for example 2006, 2007.

Answer 3

More than likely you made them on the 2006 version, and since you have the 2005 version, it won't open. Try opening it on a 2006 version and it may help.

Answer 4

Down load this program from dwg gateway it will allow you to open any autocad drawing and save it to any other dwg version.

And the best part its free!

Regards