|I have solved the issue. |
My built-in mic of Toshiba Protege R705, ( audio seetings from Control pannel) showed that the dB was set at 100%. It should actually be at around 10% ( or may be less).
The Dragon versions 10 and 11 only are compatible with Windows 7.
If you have Windows XP or or windows 95/98 or vista then you can use earlier versions of Dragon Naturally Speaking like version 9,7,6 or even Dragon 5. However,
Version 11 is just fantastic. Almost 99% accurate.