Autocad LT 2012 won't start

[Anonymous]

My autocad LT 2012 suddenly won't start. Here's a brief history. I tuned on my pc (network pc), then opened MS OUTLOOK. After a few moments, I opened my Autocad LT 2012. After a few moments, my PC froze. Nothing more logical to do but to do a manual restart because the CTRL+ALT+DEL do not work because of the freezing. I restarted and tried opening the autocad LT 2012. It was onl upto to the loading screen to the point where it shows "CHECKING LICENSE" and after that it closes as soon as I open it. I tried accessing my CAD files directly from Windows Explorer and the same thing happens. I referred this to out vendor and did the following. 

1. uncheck the Publisher's Certificate Revocation

2. repair/reinstall

3. uninstall and then reisntall

4. created another user name on the same PC.

All of those never worked. My pc specs are the following:

Windows 7

Intel Core i3 CPU 540 @ 3.07 GHz

4gig of RAM

32-bit operating System

This problem occured about 3days ago.

[Charles_Shade]

What changed on the OS three days ago?

Look at System Restore to see.

At this point you likely need to start over with the install:

Remove Autodesk Products:
http://usa.autodesk.com/adsk/servlet/ps/dl/item?linkID=9240817&id=2887771&siteID=123112

You may need to look into removeing all the .NET installs on your system and reinstalling these as needed.

2012 needs MS .NET 4.0 Framework. The install of LT should place this for you.