What should I do now?

[ewok]

What is the name of your state (only U.S. law)?
Texas

My mother applied green card (unmarried child of a US citizen) for me in 2003. The case is approved in 2007 by CIS and we were notified by NVC to pay $70 USD fee and submit a form to NVC in October 2009. The fee and form were sent right away. However, I was told by a relative to send e-mail inquiry to NVC to express my intention to change status in the US, as I am currently study here for PhD degree in a university in Texas (with valid I-20). I later knew that I should follow the procedure of application for green card, so I've been waiting for the notice of interview. Today, I got an e-mail from NVC and the contents of the e-mail is as the followings:
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Your inquiry has been received at the National Visa Center (NVC). The NVC received notification of the beneficiary's intent to adjust status in the United States. The NVC does not process adjustment of status cases. We will hold the petition at the NVC until we are notified by the U.S. Citizenship and Immigration Services (CIS-formerly known as INS) to return the petition to them. To apply for adjustment of status in the US you must contact the nearest CIS office and submit a copy of the approval notice (Notification of Immigrant Visa Approval) sent to the petitioner by CIS. Please note that there are certain eligibility requirements for using Form I-485 (Application to Register Permanent Residence or Adjust Status). Forms are available by calling 1 (800) 870-3676, or by submitting a request through the CIS website, [url=http://www.USCIS.gov]USCIS Home Page[/url]. All future inquiries regarding adjustment of status should be directed to the CIS either through the website address listed above or by calling the USCIS National Customer Service Center. The USCIS National Customer Service number is: 1 (800) 375-5283. The TTY number is: 1 (800) 767-1833. Please be advised that since the beneficiary has chosen to adjust his/her status with CIS, all fees and forms previously requested by the NVC should be disregarded.
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If I decide not to adjust status in US, what should I do? If I want to adjust status in US and file the I-485 form, how long will it usually take for me to get green card?

[evcalyptos]

[url]http://forum.freeadvice.com/immigration-9/can-i-have-my-green-card-interview-u-s-488826.html[/url]

Look up the I-485 processing times for YOUR local office at uscis.gov (6 - 12 months).

You're the one who will have to decide what to do.

[ewok]

Thanks for the answer.
I read again the I-797 that we got in 2007, it says clearly I am NOT eligible to file I-485 (due to my current VISA type). Then, is my immigration VISA process affected by my last e-mail to NVC?