Okay, I have a terrible HP Pavilion 743a that came out around 10-11 years ago and I really want to sell it (I've been using a great laptop for a while so I haven't been using this HP Pavilion thing for ages.) What I'm trying to do is make the old Pavilion decent enough to sell so I can get more money off it. Here are it's terrible specs:

Intel Pentium 4 CPU @ 2.4 GHz (Single Core, very bad processor...)
80GB HDD (Really, really small space!)
512MB PC2100 DDR SD Ram (Another reason to why the computer is bad)
Nvidia GeForce4 MX420 (Only 32MB DDR Video Memory!)
Windows XP Home

^ This wouldn't sell for much at all, so here's what I'll try to do without spending too much:

Intel Pentium 4 CPU @ 2.4 GHz - I've been looking around for what I can upgrade it to, and this is what I found, but I have a question. The max TDP of the current processor is just under 60 Watts, but I don't know if 65 Watts can run on this computer. I don't know much about how the max TDP works.

80GB HDD - I found this. It's cheap-ish but it would hopefully increase the value of this computer.

512MB PC2100 DDR SD Ram - I can get this, but the computer's specs say that 1GB is the max it can hold. If I add this to the 512MB ram, will it be a problem having 1.5 GB?

Nvidia GeForce4 MX420 I know that this graphics card is definitely one of the worst cards to use nowadays, but is it really necessary to get a better one if the processor can't get much better anyway? Bad Processor and a good graphics card won't really work right?

Windows XP Home Someone I know can easily give me Windows 8 Pro for free, but if I add the 1 GB ram will this computer meet the requirements to get Windows 8 Pro?

Can I have some advice on how I can make this computer slightly better?