1Is it on Vista. Try to uninstall the updates
2You can have this error if you use USB drive in previous sessions and dont use it in current. Try to use a USB drive in place, and AuotCad opens fine. It doesn't have to be the same USB drive, Windows just has to have the drive available
Good Luck

Almost of you has the same problem,, i have many askers about that problem and they are extremely solve it by looking and analyzing in this blog properly
http://blog.jtbworld.com/2006/12/autocad-error-aborting-fatal-error.html
try to open this blog theres a lot of people who suffering that error, but they are the one who fix it, by sharing there idea's try it,, GO!!

What were you attempting to do when you get the message?

- If you use AutoCAD's hardware acceleration, please switch it off. Do this
in the AutoCAD Options > System tab > Performance Settings > Manual Tune >
clear the "Enable Hardware acceleration" check box. (Use ... > Performance
Settings > View Tune log to verify the recommendations for your system.)
- Have a look at the entries in Event Viewer to see whether it contains more
details on the error and whether others applications might have problems as
well.
- If you login as Administrator or another user (create a new one and try),
does the error still occurr?
- Reboot the machine in secured mode to see whether the error still occurrs.
If not, make sure your graphic card's and other hardware drivers are using
the latest drivers.
- What other Autodesk products do you have installed (product and version)?
- Is this the only machine with problems? If several, is the hardware
different or the same?

AutoCAD Error Aborting Fatal Error: Unhandled e0434f4dh Exception at 7c81eb33h Solution This error occurs if Autodesk Map Skin is enabled and Microsoft .NET Framework 2.0 is installed on the machine. There are two ways you can correct this issue: At the command prompt, enter MAPSKINMAP to disable the Map Skin. Uninstall .NET Framework 2.0.

There is a corrupted file for that software and the best way to resolve that is to uninstall and reinstall the software to your computer...