The first thing you really want to do is to download the standalone installer for SP3, using another computer, then transfer it to the machine in question.. You'll not be able to do it on that one, because IE6 (which is the worst version ever of IE.....and so far out of date it's actually dangerous) won't update until SP3 is installed. Then IE6 won't update until the updater has itself been updated.....and so on, and so on. See my post here:-
If you're determined to stick with XP, I'd consider re-installing another version of XP. See here:-
This includes the POS-ready 'hack' which means you keep receiving security updates until April 2019.....and SP3 is 'built-in'.
Do follow the advice about being careful, and applying all the usual cautions. Having said that, I can personally vouch for this version, having used it for almost 18 months. The only reason I can now post links to this stuff is because XP is now considered by the staff here to be 'abandonware', so the rules for links to software for XP have been relaxed.
I see the Dimension DE051 can take up to 2 GB RAM. It would be worth 'maxing' this out if at all possible; extra RAM always helps. How much is installed at present, do you know?
There is, of course, another alternative. Have you considered Linux.....which is totally free to download and use? If the idea appeals, BC has a very active 'Linux & Unix' section, where we'd be more than happy to help you choose something that would run on the old Dell. (Dell's are, by and large, pretty good with Linux!)
Don't be afraid to ask questions, no matter how silly you might think they are. That's the only way to learn!
Up to you, of course.
Edited by Mike_Walsh, 15 December 2016 - 05:23 PM.
Distros:- Multiple 'Puppies'..... and Anti-X 16.1
My Puppy BLOG ~~~ My Puppy PACKAGES
Compaq Presario SR1916UK; Athlon64 X2 3800+, 3 GB RAM, WD 500GB Caviar 'Blue', 32GB Kingspec PATA SSD, 3 TB Seagate 'Expansion' external HDD, ATI Radeon Xpress 200 graphics, Dell 15.1" pNp monitor (1024 x 768), TP-Link PCI-e USB 3.0 card, Logitech c920 HD Pro webcam, self-powered 7-port USB 2.0 hub
Dell Inspiron 1100; 2.6 GHz 400FSB P4, 1.5 GB RAM, 64GB KingSpec IDE SSD, Intel 'Extreme' graphics, 1 TB Seagate 'Expansion' external HDD, M$ HD-3000 'Lifecam'.