Given that you were lawfully admitted into the country upon your last arrival,
you will be ale to file for adjustment of status in the US and will not need to depart and file the waiver to be readmitted. That waiver requirement is not applicable to you since you were lawfully admitted into country and are thus free to apply for a green card and obtain it in the US.
Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
I assume that you married a US citizen after you came in the US the last time. In that case you do not need to file I-601. I-601 is an Application for Waiver of Grounds of Inadmissibility. You were admitted in the US, therefore, you were admissible at the time you received your visa.
When you were in the US 7 years ago and overstayed for two years, then departed, you incurred a 10-year bar to adjustment of status.
However, if when you were here 7 years ago, you were on an F-1 visa with "D/S" indicated on your I-94, then you might not have accrued the unlawful presence and would not need the waiver now to be able to adjust status.
Obviously, be sure to discuss this in detail with a good immigration attorney. Most of us are available via phone and Skype.
Attorney Khurgel is a former USCIS and State Department Embassy Officer. His comments on Avvo are general advice, and do not constitute an attorney-client relationship.