Thank you very much El Polo. To be honest, I'd say reformatting and starting from scratch is a bit unnecessary (or at least, premature) in your case. And it would be really pity if we didn't find the cause of the problem, too. You're obviously not the only one who's got it (see e.g. busterkeaton's post above) so it must be something that's not really so specific to your machine. Also, the fact that the machine rebooted and you didn't see any BSOD doesn't necessarily mean that no BSOD actually took place -- XP is preset to automatically reboot after BSOD, and if full dump generation is not enabled (which is not, by default), the reboot can be so fast you won't even see the blue screen. If you want, I can help you analyze that problem, too. Just send the contents of the \windows\minidump folder (ideally ZIPed up) to my email address and let me see what I can do...
Anyway, now back to the U3 issue. Thanks for spotting the error in the cmd file - you were right, the U3_APP_DATA_PATH should have been set to point to your U3 removable drive, and you did right when you changed it to H:.
However, I'm not sure I understand what happened after you ran the fixed version of the cmd file. Did it make any difference at all? Did the avast splash screen appear on the screen, followed by the "Fatal error: cannot load language DLL" error box? Or nothing at all? Also, you're saying this created a new file "setup.exe" in the Exec folder? And nothing else?
Thanks
Vlk
Thanks
Vlk