"Great" is over used, but I understand the perspective; But it's not a selling point here in appraisals.
It's $200 as a delivered build with the Win7 disc in hand to the buyer, $175 w/o the disc. I'd obviously aim for a wiped build and keep the Win7 disc for myself. It sounds harsh, but no one is looking for this stuff. If they are, they have little money to spare for such things as computers.
An option is to donate it to a qualified charity and write off it's full worth on taxes. I haven't found one church that isn't qualified. Whether you like that church or religion or not, it's a good way out as far as write-offs go and PC stuff. Charity organizations are always looking for charity. Charity doesn't mean the giver has to feel all good and rosey about giving stuff away, but just them that are asking for charity. In this case, you give them $175 worth of stuff and can rightfully write it off as $300; and that helps you too. "Qualified" is a big thing here, so just don't give it away willy-nilly. I'm not giving tax advice, but if this $300 puts you over the edge of a good filing, it can come back and bite you in an audit.