Windows shell commor

Hi Tanvi, AV softwares are .exe files. If you want a good free AV solution, delete Norton - it's really no good. Download Avast Anti-virus or AVG Anti-virus or Avira AntiVir Personal.

Personally, I'll recommend Avast, but it's upto you. All these are free. If you have any queries, you can post back in Hindi or PM me if you want.

DLM stands for Down Load Manager. As you downloaded your copy of Norton Antivirus this is normal.
Your download file maybe corrupt. Try downloading it again.
After you complete the download and before installing shut down any anti-virus you maybe running.
Also run the Norton Removal Tool to remove any trace of a failed installation.
http://us.norton.com/support/kb/web_view.jsp?wv_type=pu...

Then try installing the Norton AV again.

Still having problems? Run by the Norton support forums.
http://community.norton.com/