Hi All, the issue has sorted out by the 24/4 customer support executive... Thanks to one and all for your replies...
Problem: If we try to select an object or text, its not selecting. Even the text is not highlighting if we double click to select the texts. It happend only wen we select the objects by its edges (its hectic and worse like the stinky coreldraw)
Issue has been solved by Resetting Adobe Illustrator by below steps...
1.Go to "C:\Users\Admin\AppData\Roaming\Adobe"
2. Duplicate the folder"Adobe Illustrator 18 Settings" to "Adobe Illustrator 18 Settings Old"
3.Then enter into "Adobe Illustrator" folder
4. Then rename folders "18.0.0" to "18.0. old" "18.1.1" to "18.1.1 old"
5.Restart AI, Error fixed...