Hi, I can see there is a lot of misinformation in this thread. First though to address Littleone's most recent question.
I believe the is issue for this person is not really about how they feel towards JWs or the religion or about going on with their life. It is the state of being labeled officially DF'd that apparently presents the problem. This is because of the org's rules with respect to not associating with a DF'd person. So you see, if this person has JW family members or even just friends that they would like to associate with it would be important to get the baptism annulled with the resulting view that the DF'ng would also be nullified.
This is I believe an erroneous notion.
Getting one's baptism annulled would not necessarilly remove the negative social affects of shunning that result from the DF label. Shunning is actually a choice by the members (some including myself would argue that it is imposed or coerced) as to whether they will "fellowship" with another person.
DFng is only a major category that results in shunning but it is not the only one. Those DA'd, those "marked" and former and even non-JWs who engage in anti-JW activity (thus considered apostate) are also shunned.
The extremely rare examples cited by others in this thread who successfully had their first baptism annulled apparently and I suspect evidently had nothing to do with disfellowshipping. In fact in one case the poster mentioned that the person was actually rebaptized.
Rebaptism used to occur more frequently in certain situations but I think it is extremely rare today. Actually as a humourous aside, the reason that the brother asks the person just immediately prior to their getting ready to go to the pool if they have ever been "baptized before" and notate the congregation is because JWs believe that the symbolic act actually has cleansing power from sins and they do not want a DF'd person to get baptized again or else it would nullify the underlying sins. (Seriously.) Thus in theory, a DF'd person could go to another location pretend to be a newly interested one, go through the process and get baptized. Of course you may wonder wouldn't a person just lie and say it is their first time the answer to which is "of course" but still JWs make the attempt.
Getting back on track, one poster above said that only baptized persons are DF'd and this is true in the technical sense. But as I have already pointed out, the reality is that the shunning practice itself is broadened to several other groups. For example, if the person is considered "apostate" (which is supposed to also only be applied to once-folded individuals) because of their anti-JW activity, the social effect would be the same or even greater than being DF'd. So what I am saying is that if a person did get their baptism overturned.it would not necessary remove all of the social stigma.
Turning to some other misinformation here. Others have referred to baptism as being "contractual" in nature. They have even asserted that the Society holds this view which is incorrect. Some have said that just as a minor is not considered competent to enter into a legally binding contract prior to age 18 (in many jurisdictions) that the same should be true of baptism. Well actually this analogy is wrong, though appealing, but I will go ahead and enlighten you and say that while it is true that in most jurisdictions there are such provisions that allow minors who enter into a contract to have the contract voided ab initio, there are also a number of exceptions, including contracts that have resulted in life-benefits to the minor and contracts for life necessities.
What is more interesting to consider is whether a standard of "age of consent" (which varies widely among the states) should be applied when it comes to baptizing minors. After all, we are talking about an act that is performed upon our person that has significant social and long-term consequences and it is without exception performed by adults (who are held to a higher standard and who are presumed to possess greater understanding and wisdom, and usually occupy positions of power, dominance, authority, trust and control over the minor). Chew on that one for a while.
Finally, some confuse what the Society says and whats its lawyers discuss with regard to Disfellowshipping. It is not a "contract" discussion. What is at issue is whether such theological matters are proper subject matter for legal courts or whether they are ecclesiastical matters to be decided by a church under a (federal and state) constitution which maintains a separation between church and state. The society asserts properly that such decisions are ecclesiastical.
-Eduardo