What is emergency backup file?

I have a drawing file that suddenly becomes a file with .$$$ extension instead of the normal .dwg extension. the problem is that now i cannot open the file for editing. it says that it is an AutoCAD emergency backup file. what is that? How am i going to change it to dwg again?

please help! my project is now in jeorpady....

I've not seen one of those. Do you have RECOVER in 2009? Give that a try.

I'd suggest following Dave's advice and use the DRAWINGRECOVERY command. It can be invoked at the command line (type it just as you see it in the previous sentence) or you can find it by looking under the big red "A" by clicking on Menu > File > Drawing Utilities > Drawing Recovery Manager.

For more information please consult your 2009 Help files. Using the Index tab type in the word RECOVERY. This should bring up the topic RecoveryMode System Variable. Open the topic. You'll see three tabs: Concept...Procedure...Quick Reference. Read the contents of each. It may not only help to solve your problem but it will also make you a bit more knowledgeable about the topic should the problem arise again in the future.

Personally, I know of the .SC$ file extension but .$$$ is new to me too. Did you, or someone else in the company, elect to change it (can that be done?)? Just curious.

I Had It Happened Few Days Back But From My Memory The File Extension Was $0$. I Was Able To Recover It By Simply Renaming In Explorer As .dwg