QupZillaPortable does not start on my system and on an almost similar configured one as well: WinXPSP3, no Java, no .NET, no updates, pretty much stripped down to the minimum.
I can only see the usual portbleapp screen for a few seconds but after that nothing happens. No error message. Program not running, not in the task manager.
The same with the 1.4.2 version
I tested it also with the PortableFreeware version 1.4.3 but it just states I need to reinstall and quits as well.
I think it depends on something that is usually installed.
QupZilla seems to be beside Avant (unfortunately no portableapps version) the only in-development lightwight browser and I need one for an older computer with max. 512MB RAM.
If I can help with testing let me know.