OI own a compaq 5304. Its an in exspensive PC but its all we can afford.My question is that apon start up the tower groans and growls.It gets less loud as it warms up and sometimes no noise at all. It does come back intermittently during use. My wife just vacumed the back and got some dust out from the fan area.I understand that they all humm a little bit but this is fairly loud when you first turn it on. Anyone expirience this and are there any remidies or Ideas what it may be? .....Thanks in advance Mark