I have 2000 lt  in XP and 2011 in windows 7 on the same computer when I tray to save 2000 lt in to 2011 lt I get a massage that says you do not have permission to save to this locationIt will open I can make changes but I can not save ithow do I fix thisThanks Bill

OK I'll take a shot at it :) First you haven't explained the problem very clearly. There is no need to save a ver 2000 drawing to a ver 2011 drawing. If you are using 2011, you can open the ver 2000 drawing no problem. Any problems with saving have to do with your windows setting, such as it being on a network, or the file is write protected, etc.  Can you save the drawing if you rename it?  If you start a new drawing in 2011, can you save it to this same "location"? -it's nice that you can get a "massage" while on the job :)  

There are two threads by the same person about the same problem.  They should be combined.It sounds like a "permissions" problem to me and has nothing to do with what version of AutoCAD you are using.  As Carl has stated ACAD 2011 can open any drawing file from an earlier release.  The only drawing file it can't open would be one saved to the 2013 dwg file format.