You can't download security updates for Windows XP through Windows Update or Microsoft Update anymore.
We like this OS because it's faster than the later OSes, at it doesn't have the WDDM overhead unlike the later MS OSes.
From now on, I'm talking about Windows XP (x86, x64) computers only.
It is recommended to have a router for internet connectivity (a Windows XP computer must have a private IP address like 192.168.xxx.xxx, or 10.xxx.xxx.xxx, or 172.16.xxx,xxx, with no alien Windows XP computers on the same subnet).
If you use your computer only for crunching (no browsing nor e-mails), then you are still safe.
If you do use your Windows XP computer for everyday tasks, then it's not recommended to use Internet Explorer for browsing.
But...
Since the server version of this OS (Windows Server 2003) came a year later, that OS still has support from Microsoft.
So you can install Windows Server 2003 to have a little more OS support. :) I'm just kidding.
It's not worth the time and effort, since you can download the security patches of Windows Server 2003 from Microsoft's website, and install them manually on Windows XP! (no, this time I'm *not* kidding)

It works only on Windows XP x64 Professional SP2

I'm trying to figure out how to make it work on Windows XP x86 SP3
(I have to mess with the .inf file in the update, which ruins the integrity check, and I don't know how to avoid that)

x64 versions:
KB2957503
KB2957689 - Cumulative update for Internet Explorer 8
KB2957482 - Security Update for Microsoft XML Core Services 6.0 Service Pack 2
KB2957509
KB2939576

You can use a simple registry change to convince the update service, that this is an embedded system which has support up to (I think) 2019. Just put this into the registry (copy content to a .reg file and launch):

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\WPA\WES]
"Installed"=dword:00000001

You can try to update your system with wsus offline downloader and server 2k3 updates witch are available there.
____________
DSKAG Austria Research Team: http://www.research.dskag.at

You can use a simple registry change to convince the update service, that this is an embedded system which has support up to (I think) 2019. Just put this into the registry (copy content to a .reg file and launch):

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\WPA\WES]
"Installed"=dword:00000001

You can use a simple registry change to convince the update service, that this is an embedded system which has support up to (I think) 2019. Just put this into the registry (copy content to a .reg file and launch):

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\WPA\WES]
"Installed"=dword:00000001

Thanks, it's working (only on x86 systems).

You can try to update your system with wsus offline downloader and server 2k3 updates witch are available there.

Yes i mean exactly that tool :)
____________
DSKAG Austria Research Team: http://www.research.dskag.at