Funny... after a couple of days lurking around in the forums, I never realised WinSetupFromUSB even existed! Anyway, had a little more time today and started from scratch again using Ilko's fine creation. I managed to get the x64 installation running, but I'm still having problems when I try to get XP SP3 and x64 to play nice together. My procedure is as follows: Execute WinSetupFromUSB 0.1.1 Select Windows XP SP3 as source Format drive FAT32 Check 'Copy setup boot files only' Click Go I then tested the USB stick to boot my machine. Setup enters fine. Execute WinSetupFromUSB 0.1.1 again Select Windows XP x64 as source Check 'Copy setup boot files only' Click Go Dialog box 'Folder $WIN_NT$.~BT exists' opens -- YES to rename to .BKP, NO to delete, Cancel to return to menu I select Yes to rename. I return to boot my machine with USB and everything seems fine, but when selecting XP SP3 to install, it looks like the SP3 setup is pulling the files from the x64 install. That is, when I put my USB stick into a 32-bit machine, XP SP3 cannot load the setup fully. (Error is: Ntkrnlmp.exe Could Not Be Loaded. The Error Code Is 7) Thing is, I can get the x64 setup working by itself without other Windows installations on USB... but ultimately, I'd like to use this for more than just one-off installs! I'm still very new to multi-booting and USB installs and still need a lot more understanding in these subjects. I'm definitely going to investigate Wimb's links and do more background reading on PE while I'm at it! Btw, what other MS OSes are one-off installs without the PE environment? Just the 64-bit OSes? Thanks again