TCP/IP Patcher (change the number of possible open connections in Windows XP and Server 2003):
EvID4226Patch223d-en.zip
(From here: http://www.lvllord.de/?url=tools)

Windows post XP SP2 defaults to allow just 10 connections, which sucks when you’re trying to make hundreds of connections at a time when downloading files. I usually kick my connection limit to 1,024 connections.

UXTheme Patcher (use unsigned themes in Windows XP and Server 2003):

uxtheme21.zip (Universal 2.1)

Old Neowin:
nw_uxpatcher4.zip (5.5)

Older Neowin:
nw_uxpatcher4.zip (4.0)
(From here: http://www.neowin.net/forum/index.php?showtopic=140707

(Page ID: 467)