These files can not be deleted by Disk Clean ' and also how to know the location of these files so that these can be deleted from DOS via Command Prompt

For this you need a software.

Advance System Care
You can download it from http://download.com its free software you need not to upgrade the software.

Click the link to download the application

http://download.cnet.com/Advanced-SystemCare-Free/3000-2086_4-10407614.html?tag=contentBody;mostPopTwoColWrap

Run the software to clean the junk files.
Bye