Dell inspiron 2650

Well I am a beneficiary of a headache I should say, not only has it elapsed but whoever was the original owner of this dell inspiron I have won and have purchased on ebay must have not extended services therefore my request for a backdoor pword would cost me $$$...any other solution to this? I just need to install a new o/s and not tamper anything hardware wise....not savvy with the solder unsolder process...that's why im here right??? well, hopefully someone has a better idea than what im about to do if nothing else resets it...install knoppix and partition it