Almost all criminal records last your entire lifetime. Felony convictions remain on your record forever, but so do convictions for misdemeanors. A criminal record severely hinders your job opportunities, housing options, credit line, public benefits, and other privileges usually taken for granted. If the misdemeanor is minor, however, an employer or landlord may not find the blemish to be a cause for concern. If you are convicted of a crime as a juvenile, you develop a record, but it may be sealed once you reach a certain age (18 or 21, usually). However, a sealed criminal record still exists, and will still turn up during a criminal records search; only the contents of sealed records will remain off-limits.
Expunging your record is really the only way to erase a criminal record. To be accepted for expungement in most states, you have to fit very specific criteria and then undergo an extensive review process than can include meeting with judges who sentenced you in the past. For example, if you are convicted of a small crime at an early age but serve your sentence and exhibit excellent behavior for several years, you may be eligible. It is best to consult a lawyer if you think you may be eligible, especially because you will likely need help filing the correct paperwork and presenting yourself and your case in the best manner. Expungements are rare, but they can erase the record, which will definitely have a major impact on job and housing applications. Expungements do not, however, erase your record in the eyes of the law. Should you be convicted for a new offense after your expungement, your prior record will factor into the conviction and sentence that await you.
Remember, the ultimate key to eliminating a criminal record is to avoid having one in the first place!