I just got an ac adapter for a computer one of my friends had given me, not that old a Sony Vaio pentium 4, windows xp so it's not completely dated. The computer hasn't been on in probably over 9 months because the ac adapter broke and she never wanted to get another one. I plugged in the adapter, lights up on the adapter box but I'm getting no response at all from the computer. Is it possible the battery just needs to charge for a while because it's been off so long? If so how long should I charge it for before I figure it's something else?