Hi I have on my PC a message that the Hard Disk Drive is getting low (512Mb to start with)and I cannot delete anything more.So I can buy a new Hard Disk drive can I and replace the old one? Or should I add a new one alongside the old one? Also I have no idea what to do or what is compatible with my Dell Dimnesion 2400 series. Is it easy or should I just get someone in to do it? :( All this talk of master and slave and changing this and etc is beyond me..I open the back of PC and am lost immediately and have not bought one yet lol Thanks.