I swap around hard drives like underwear. And yes it isd Pentium 4. No problems. I have newer laptops but still use the Dell without any issues. Also not much difference with a single core and my dual core AMD laptops.
It all depends on your needs.
I’ve been using an AMD Duron 1300 since around 2003. It just blew on me a few months ago - replaced with an old Soyo Dragon Ultra MB that was loaded with...another Duron 1300. Its a XP w/2GB box - just to run an Apache server and few older image editing packages that I prefer (Micrografx Picture Publisher Ulead Photo Impact, Swish). So - more cores isn’t going to make a ton of difference running software that old or serving pages across my network.
Nothing archival. I dont use it on the web - but I do have it networked so I can access the edited files on my newer, faster Zotac/Linux box that I do the majority of my work on. And I have a nice stack of IDE drives. I still get some real work out of that Duron machine - but not sure having it up to date with SP3 makes any difference.
For the record - I do have 2 Macs - Power Mac G4 that runs 10.4 that I use for checking web layouts in Safari. Got that at a garage sale for 5 bucks! I can’t update to the latest Safari or Firefox on that system. I think there is a security update or something that needs to be run. And an iBook G4 which gets stuck at boot asking for “Disk 2” with some message I can’t recall.