You can register the system online, which will change your warranty start date.

www.dell.com/.../retail

I have purchased it from Store.  My invoice date is 17th July 2013. I had a talk on phone with Dell's technical department, they told me to contact dell's billing department and send them a copy of invoice to update the warranty period, but I do not have email id of dell's billing department.

Warranties usually start on the invoice date. Did you purchase online or at store?

Hi Nimesh,

We apologise for the inconvenience caused to you.

Please register your system online as suggested by Ejn63, however, in case of any difficulties, please contact me through private message by clicking on my name highlighted in blue. On the next page, click the envelope icon and provide your service tag and contact information (as mentioned below) so that I may access your system records.

• System Service Tag No.:
• Registered System Owner's Name:
• Shipping address:
• Telephone number/s:
• Email address:

Thanks and regards,
Babita S
#iworkforDell 

For easy access to drivers, manuals and product updates, please visit our Support Site .

Thanks Babita.  I will do the same.

Hi Babita,

I have done the steps shown by you.  But still the warranty date is not updated.  Have entered all the detail in form.

Regards,

Nimesh

Hi Nimesh,

We apologise for the inconvenience caused to you.

In order for us to assist you further, please contact me through private message by clicking on my name highlighted in blue. On the next page, click the envelope icon and provide your service tag and contact information (as mentioned below) so that I may access your system records.

• System Service Tag No.:
• Registered System Owner's Name:
• Shipping address:
• Telephone number/s:
• Email address:

Thanks and regards,
Babita S
#iworkforDell 

For easy access to drivers, manuals and product updates, please visit our Support Site .