Or take a look how BootIce (also free tool) does it on any system starting with XP or PE (as I have tested).
I tested your 2 ISOS way for XP install using v22 unattended and 4.0PE (just the one make from AIK for Win8 deploy, nothing added) as second ISO on a machine with multicard reader and it fail after formating de internal IDE HDD (160GB disk) first volume (20GB) and reboot, it didn't boot there was a screen:
Try (hd0,0): none-MS: skip
Try (hd0,1) : invalid or null
Try (hd0,2) : invalid or null
Try (hd0,3) : invalid or null
Try (hd1,0) : NTFS5 : No grldr
Try (hd1,1) : invalid or null
Try (hd1,2) : invalid or null
Try (hd1,3) : invalid or null
Can not find GRLDR
Press space bar to hold the screen, any other key to boot pevious MBR ...exF
Remove disk or other media.
Press any key to restart.
Thinking it is related to multicard reader, I open the case and unplug it. Same thing every time I reboot that machine with the USB pluged I get same screen.
I unpluged the internal HDD and put another IDE 10GB (only one partition) and rebooted. Same thing very time I reboot that machine with the USB pluged I get same screen.
Trayed on other machine 80GB IDE HDD (20GB first partition active) and it boots OK from USB, trayed then the XP install. Same thing every time I reboot that machine with the USB pluged I get same screen.
I unpluged the internal HDD and put a second IDE 10GB (only one partition) on second machine and rebooted. Same thing every time I reboot that machine with the USB pluged I get same screen.
If I tray other USB stick on any of them they boot from that USB just fine.
I reformated the USB and trayed again in all configurations and no change, Why? the two machines boted fine first time with 160GB HDD first one and 80GB second one, after traying to install they don't boot from HDD or the USB stick with your v22 any more but they boot from any other stick.
Best Regards
Edited by alacran, 29 April 2013 - 07:42 PM.