When I start AutoCAD, it takes too long time to response, how can I resolve this issue?

Increase u r RAM, use latest processor, empty u r temp folder and Recent files folder.

It may depend up on which version of AutoCAD and what are you are Resources like RAM & Processor Speed.., and Try to empty the temp folder.., and remove all the .bak files .bak extension files are temporary data storing files whenever you open the dwg it will open a .bak file try to empty them check for any attack of malware or Virus on PC it may cause too .., and if you are using authorized autocad then you can contact autodesk forum directly post your Question http://forums.autodesk.com try to look at the following for further more info.., http://forums.autodesk.com/t5/AutoCAD--DWG/Autocad-2012-amp-2013-sometimes-hang-very-slow/td-p/3530110 Cheers

what is your computer specification RAM CPU Cache Video Card capacity

You must possess4 GB RAMat the very least System requirements for AutoCAD: http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=&linkID=9240617

if you use autocad2007 this is true it's response is too slow i recommend to use autocad2010 or2013